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Sri Lanka Association for the Advancement of Science Proceedings of the 66th Annual Sessions – 2010, Part 1-Abstracts

Sri Lanka Association for the Advancement of Science

Proceedings of the 66th Annual Sessions 6 – 10 December, 2010 Part I: Abstracts

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ISSN 1391-023X Proceedings of the 66th Annual Sessions Part 1 – Abstracts 06 – 10 December, 2010

© 2010 December The material in this publication has been supplied by the authors, and only minor copy editing, if relevant, has been done by the SLAAS. The views expressed remain the responsibility of the named authors and do not necessarily reflect those of the SLAAS or any other organization or body sponsoring SLAAS acitivites.

Sri Lanka Association for the Advancement of Science Vidya Mandiraya, Vidya Mawatha, Colombo 07, Sri Lanka

Edited by:

Hema Goonatilake, Editor Mayuri R. Wijesinghe, Assistant Editor

Compiled by:

I.M.K. Fernando

Printed by Ananda Press (Private) Limited This Publication is sponsored by the National Science Foundatiom ii


Contents Section A Medical. Dental and Veterinary Sciences …………………………

01

Section B Agricultural Sciences and Forestry …………………………………..

13

Section C Engineering, Architecture and Surveying …………………………

40

Section D Life and Earth Sciences …………………………………………………….

57

Section E1 Physicsal Sciences ……………………………………………………………

77

Section E2 Chemical Sciences ……………………………………………………………

93

Section F Social Sciences …………………………………………………………………

111

Posters Section A ………………………………………………………………………...

127

Section B …………………………………………………………………………

131

Section D …………………………………………………………………………

138

Section E2 ……………………………………………………………………….

145

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Oral Presentations

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Section A 101/A Correlation of clinical presentation and laboratory confirmation of dengue patients N H Manamperi1, A M M H Athapaththu1, G Premawansa2, C Wellawaththage1, T D S S. Jayarathna1, W Abeyewickreme1 and M D Hapugoda1* 1 2

Faculty of Medicine, University of Kelaniya, Ragama North Colombo Teaching Hospital, Ragama.

Dengue is one of the most important arthropod-borne diseases in the world and it has become a very important disease in Sri Lanka, today. In Sri Lanka, diagnosis of dengue depends mainly on clinical signs and symptoms. Only a few suspected patients are confirmed by laboratory assays based on aetiological agents. The objective of this study was to determine the correlation between clinical presentation and laboratory confirmation of dengue patients. Acute serum samples (n=100) collected from patients clinically suspected of having dengue fever (≤ 5 days) warded at the North Colombo Teaching Hospital, Ragama were used for the present study. Serum samples were collected after obtaining informed written consent from patients and samples were tested by RT-PCR which has high sensitivity (10 FFU/reaction) and specificity. Final diagnosis as dengue or non-dengue was assigned based on the results of RT-PCR assay. Differences in clinical and laboratory data were analyzed in dengue and non dengue patients. Chi-square test was used for comparison of data. The proportion of laboratory confirmed dengue patients were 56% (56/100). Mean platelet count and PCV in laboratory confirmed dengue patients were 60 269/mm3 (range 3000-306000) and 41% (range 27-61%) and in non dengue patients were 106 318/mm3 (range 5000-290000) and 41.6% (range 29-53%). Based on WHO criteria for diagnosis of dengue, headache (48/56 vs 41/44, χ2=0.7, p=0.38), retro-orbital pain (30/56 vs 14/44, χ2=3.8, p=0.04), limb pain (51/56 vs 30/44, χ2=7, p=0.00) and external bleeding (29/56 vs 4/44, χ2=18, p=0.00) showed significant association with dengue. Neck pain (10/56 vs 09/44, χ2=0.01, p=0.94), and lymphadenopathy (3/56 vs 02/44, χ2=0.08, p=0.78) did not show significant association with dengue. The infection was confirmed as dengue fever in 11% (6/56) and dengue hemorrhagic fever in 89% (50/56) based on WHO criteria. Surveillance based on clinical diagnosis may result in over estimation of the disease as clinical diagnosis is not specific enough. Laboratory confirmation of dengue suspected patients is important to measure the real incidence of the disease which leads implementation of control measures. Further, this is important for efficient management of patients. Acknowledgements: Financial and technical assistance from the International Centre for Genetic Engineering and Biotechnology (ICGEB CRP/ SRI08-02) and International Atomic Energy Agency (IAEA SRI 5/042).

*

[email protected] 1

Tel: 0112960483


102/A Some observations on abundance and breeding habitats of Anopheles sp. in Trincomalee, Sri Lanka P A D H N. Gunathilaka1, M A S T Fernando1, M D Hapugoda1&2, P Wijeyerathne1, A R Wickremasinghe1&2 and W Abeyewickreme1&2* 1 2

Tropical Environmental Diseases & Health Associates, No 3, Eli Bank Rd, Colombo 5. Faculty of Medicine, University of Kelaniya, Ragama.

Malaria is one of the most serious vector-borne diseases affecting millions of people in the world annually. More than 90% of the deaths, resulting from malaria occurred particularly in children aged 1-5 years. Despite the huge burden and the absence of an effective vaccine, few tools are available to control malaria. Malaria is transmitted by Anopheles mosquitoes. The abundance of Anopheles mosquitoes was not studied in some parts of the island, especially in North and East areas over 30 years because of the ethnic conflict. The main aim of this study was to explore the habitat range and distribution of Anopheline species in the Trincomalee district. Five hundred and seventy one Anopheles larvae were collected from different breeding sites in 5 areas (Sirajnagar, Hatharaela, Paraipanchankulam, Indiwewa and Uppuweli) in Trincomalee district in March 2010 using standard larval collection techniques. These areas were situated about 10 km apart from each other. Collected mosquito larvae were transferred to the laboratory and reared. Emerged adult Anopheles mosquitoes were identified using taxonomic keys. Nine anopheline species were recorded: Anopheles culicifacies 6% (32/571), An. subpictus 25% (145/571), An. vagus 23% (134/571), An. peditaeniatus 5% (28/571), An. nigerrimus 35% (200/571), An. barbirostris 2% (14/571), An. jemesi 1% (7/571), An. pallidus 0.3% (2/571) and An. varuna 0.3% (2/571). Overall, Anopheles nigerrimus, An. subpictus and An. Vagus were the most prevalent, and An. culicifacies, An. peditaeniatus, An. barbirostris, An. jemesi, An. varuna and An. pallidus were the least prevalent species. Paddy fields, burrow pits, field channels, ponds, irrigation channels, edges of tanks, mud pools and marshy lands were the main breeding sites of Anopheles mosquitoes in selected areas in Trincomalee district. The presence of some Anopheline mosquitoes which can act as potential malaria vectors may cause malaria epidemics in these areas. Acknowledgements: Financial assistance from the Global Fund for Aids, Tuberculosis and Malaria (GFATM) (Round 8)

[email protected]

Tel: 0718733812 2


103/A National and international travel: A challenge to elimination of malaria from Sri Lanka P H D Kusumawathie1*, M Rajapakshe2, S M L Senaratne1, R R Abeyasinghe3 and G N L. Galappaththi3 1

Regional Office, Anti Malaria Campaign, Dutugemunu Mawatha, Watapuluwa, Kandy National Research Council, Bauddhaloka Mawatha, Colombo 7. 3 Anti Malaria Campaign Directorate, Narahenpita, Colombo 5. 2

Forty three malaria patients were reported in the Kandy and Nuwara Eliya districts between January 2009 and May 2010. These patients were investigated as per the current policy of the Anti Malaria Campaign to identify the risk factors, source of infection and the potential risk of malaria transmission in the two districts. All notified malaria patients by the public and private health facilities (hospitals and mobile malaria clinics), Anti Malaria Campaign (AMC) directorate and the Regional Offices of AMC were investigated to collect data on the age, sex, occupation, places visited prior to onset of fever to determine the source of infection, permanent residence and use of protective measures for malaria at both permanent and temporary residence. The data were collected by a trained PHI and/or the RMO using standard malaria case investigation forms (H/AMC/P 7) developed by the AMC directorate. Of the 43 malaria patients, 32 were P. vivax, 6 P. falciparum, 3 mixed infection with P. vivax and P. falciparum and 2 clinically suspected cases. Majority of the patients were males (91%) aged between 21-50 years (86%). Also, the majority of patients were members of the security forces (67%) who had served in the northern, eastern and southern districts in the country, while 28% were civilians and one was an United Nations employee in southern Sudan. Eighty one percent (81%) of patients had contracted the disease locally while the rest was from outside the country (India:14%; South Sudan 2%; Libiya 2%). Of the patients, 12% were residents of previously malaria endemic areas while the rest were residents of areas where a potential malaria transmission risk exists in the 2 districts. None of the patients were on regular prophylactic treatment or used insecticide treated nets while staying in malarious areas to prevent malaria infections. Introduction of malaria reservoir with new species and strains of parasite through national and international travel could be a major challenge to the malaria elimination programme in the country. Prevention of re-introduction of malaria from other countries by screening at ports of entry to the country and the early detection and appropriate treatment of locally acquired infections at health facilities coupled with intensified case and vector surveillance will also contribute to moving towards elimination.

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Tel: 0774100 247

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104/A Transmission of dengue infection and density of Ae. Aegypti at a new focus in a rural tea estate in the central hills of Sri Lanka S M L Senaratne1, G A J S K Jayasooriya1 and P H D Kusumawathie1* 1

Regional Office, Anti Malaria Campaign, Dutugemunu Mawatha, Watapuluwa, Kandy

Several dengue cases were detected in the latter part of January 2010 at Wevally tea estate in the Medical Officer of Health (MOH) area Lindula in the Nuwara-Eliya district. Investigation of the outbreak in February 2010 revealed that there were 09 suspected dengue/ serologically positive (IgG and IgM positive) dengue haemorrhagic fever (DHF) cases with 01 death. Of the 9 DF/DHF cases, 3 were females and 6 were males. The age of the patients ranged from 4 - 40 years with a majority (67%) between 21-40 years. There were 2 patients below 5 years. Only one patient gave a history of moving outside the area while the rest did not give a history of moving to any dengue prevalent area within 3 months prior to onset of fever. Two entomological investigations were carried out in the area to determine the breeding sites and the density of Ae. aegypti and Ae. albopictus. The first larval survey was carried out in February 2010. During this survey 119 houses were examined for Aedes immatures (larvae and pupae) where 9 premises were positive for Ae. aegypti. In this survey, the larval density is high with container index of 8.7, house index of 7.5 and Breteau index of 9.2. Breeding sites of Ae. aegypti were water storage barrels (37 %), tyres (27 %) flower pots (9 %), polythene roofs (18 %) and roof gutters (9 %). Another entomological survey was carried out in March 2010 when 100 houses were examined where 01 barrel in 01 house was positive for Ae. aegypti. The container index, premises index and Breteau index were 1.5 %, 1 % and 1 respectively. This study shows that there was local transmission of DF/DHF at Wevally tea estate where there was no history of dengue transmission previously. The study also showed the occurrence of Ae. aegypti at higher elevations (1676 m) where Ae. aegypti has not been previously reported. This indicates that the major dengue vector, Ae. aegypti, is moving to higher elevations, surviving at micro environments and starting dengue transmission when environmental conditions are conducive. Thus, it is necessary to expand dengue control programmes to cover the central hills, including the rural estate sector, of Sri Lanka.

[email protected]

Tel: 0774100247

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105/A Meeting training challenges in infrastructurally weak areas of Sri Lanka for the national malaria elimination programme S D Fernando1*, R Wickremasinghe2, R L Ihalamulla3 and P Wijeyaratne3 1

Department of Parasitology, Faculty of Medicine, University of Colombo Department of Parasitology, Faculty of Medical Sciences, University of Sri Jayewardenepura 3 Tropical and Environmental Diseases and Health Associates, No. 3 Elibank Road, Colombo 5 2

TEDHA (Tropical and Environmental Diseases and Health Associates Pvt. Ltd.) was selected as a Principal Recipient by the Ministry of Health to strengthen malaria surveillance in the Eastern Province and Mannar District so as to eliminate malaria from Sri Lanka by 2014. The challenge for TEDHA was to recruit, train and develop skills in fever and parasitology surveillance in 112 individuals who would be able to carry out their duties at selected peripheral hospitals and via mobile malaria clinics so as to effectively manage and deliver the objectives of the National Malaria Elimination Programme. This study describes the recruitment and training of these persons to carry out surveillance for the detection of malaria infected individuals. The basic criterion for selection was a credit pass in Science at the O-Level Examination. Training was carried out at the Faculty of Medicine, Kelaniya by senior university academic staff in two batches for a period of six days for fever trainees and one month for parasitology trainees followed by a two weeks field training with the Regional Malaria Officers in the respective regions. Training included lectures, practicals and field visits. Prior to commencement of training, knowledge regarding malaria was assessed using a multiple choice question (MCQ) paper. Following the training, knowledge was assessed using the same MCQ paper, short essay questions and a practical examination. All candidates scored significantly higher at the MCQ examination paper following the completion of training as compared to the same test administered prior to the commencement of training (p95% purity per liter of culture. These 2 proteins were evaluated as potential diagnostic intermediates in ELISA separately for the detection of anti-chikungunya Immunoglobulin M (IgM) antibody using a panel of well characterized serum samples. E1 and E2 showed 60% and 67% positivity respectively. Specificity proteins were tested using serum from healthy volunteers and infected with other viral diseases. Two proteins could detect only anti-chikungunya IgM antibodies. We demonstrated that these 2 novel recombinant protein antigens can function as diagnostic intermediates. Acknowledgements: Financial assistance from the International Centre for Genetic Engineering and Biotechnology (ICGEB CRP/ SRI08-02) and International Atomic Energy Agency (IAEA SRI TC 5-042) are gratefully acknowledged.

[email protected]

Tel: (0)11- 2960483

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111/A Variation in microscopic and colony morphology and biochemical and antibiotic resistance properties in isolates of Burkholderia pseudomallei in Sri Lanka E Corea* Department of Microbiology, University of Colombo, Colombo B. pseudomallei is the cause of melioidosis. As the clinical presentation is highly variable and melioidoisis rare, diagnosis hinges on accurate identification of isolates from clinical specimens in the microbiology laboratory. B. pseudomallei is characterised as an oxidase positive, bipolar staining Gram negative rod. Colonies are initially smooth but become wrinkled after prolonged incubation and have a distinctive sweet, earthy odour. B. pseudomallei is resistant to gentamicin, polymyxin and colisitin. Isolates tend to form a pellicle in broth culture. Five isolates of B. pseudomallei, from clinical specimens of patients with melioidosis, which had their identity confirmed by PCR (Inglis TJJ et al. Comparison of diagnostic laboratory methods for identification of Burkholderia pseudomallei. Journal of Clinical Microbiology 2005; 43:2201-6) were included. Pure cultures were sub-cultured on human blood agar and sheep blood agar and inoculated into brain heart infusion broth. Colony morphology and Gram stain appearance after 48 hours and 96 hours was recorded. Time for the oxidase test to become positive was recorded. Presence of a pellicle in BHI after 48 hours was noted. Sensitivity to gentamicin, polymyxin and colistin was tested using the standard CLSI antibiotic sensitivity method. Only 2 had the typical Gram stain appearance. Only 2 had identical chalky white, dry wrinkled colonies. The others varied from frankly moist to dry and from tiny, pinpoint to large. Although beta haemolysis on blood agar is not described as a feature of this bacterium 2 isolates showed beta haemolysis on human blood agar but not on sheep blood agar. Four isolates had the characteristic earthy odour. Four isolates gave rapid oxidase positivity but in one isolate this was delayed for more than 20 seconds and subsequently completely lost. Three isolates gave heavy pellicles on BHI broth and one had none. Only two isolates showed gentamicin, polymyxin and colistin resistance. Two tested sensitive to all the antibiotics. Variation in morphology and biochemical properties in B. pseudomallei is common and may lead to misidentification and misdiagnosis.

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[email protected]

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Tel: 0777808 439


112/A Comparison of Mycobacterium Growth Indicator Tube (MGIT) method and Nitrate Reductase Assay (NRA) with agar proportion method (APM) for detection of Rifampicin resistance C Adikaram 1, J Perera 1 and S Wijesundera 2 1 2

Department of Microbiology, Faculty of Medicine, University of Colombo Department of Microbiology, Faculty of Medicine, University of Colomb

Testing of drug susceptibility prior to initiating treatment is vital for controlling and managing drug resistant TB. Drug susceptibility testing by the nitrate reductase assay (NRA) and manual Mycobacterium Growth Indicator Tube (MGIT) method has been used extensively for detection of growth. The objective of the study was to compare Mycobacterium Growth Indicator Tube (MGIT) method and Nitrate Reductase Assay (NRA) with agar proportion method (APM) for detection of rifampicin resistance. Three hundred and seventy three clinical isolates of Mycobacterium tuberculosis were collected from Chest Clinic Colombo, Chest Hospital, Welisara and Prisons of Colombo from March 2008 to May 2010. Rifampicin susceptibly tests were carried out by APM (gold standard), MGIT method and NRA with 14 days old fresh cultures. The final rifampicin concentration used was 1.0µg/ml in all three methods. Thirty one rifampicin resistant isolates were detected from among 373 Mycobacterium tuberculosis isolates by APM, NRA and MGIT methods. Twenty seven isolates out of 31 were identified as rifampicin resistant by the APM. MGIT and NRA methods were able to identify 28 rifampicin resistant isolates each. One resistant isolate was identified only by MGIT method and another 3 isolates by NRA only. The sensitivity and specificity of the NRA method was 93% and 99% respectively and there was very good agreement between NRA and APM. There was complete agreement between APM and manual MGIT methods with 100% sensitivity and 99.7% specificity. Rapid identification of drug resistance is a prerequisite for initiating effective anti- TB treatment. Newer methods (NRA and MGIT) showed a high level of agreement with the gold standard, APM. The NRA and MGIT methods are rapid and easy to perform and results could be used for timely management of patients.

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[email protected]

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Tel: 0776096002


Section B 201/B Monitoring the spatial expansion of urban heat islands in Kandy city using Landsat TM and ETM+ data N L Ukwattage* and N D K Dayawansa Department of Agricultural Engineering, Faculty of Agriculture, University of Peradeniya.

Formation of Urban Heat Islands (UHI) is considered as one of the significant environmental consequences of urbanization. Satellite images in the thermal infrared can be used for assessing the urban thermal environment as well as for defining heat islands in urban areas. Kandy city with a large population and urban size located in the central province, Sri Lanka was selected in this study to monitor urban heat islands and its spatial expansion. Landsat TM and ETM+ images were used to analyze spatial and temporal distributions of heat islands over the Kandy city in 1992, 2000 and 2002. Thermal bands of 1992 TM image and 2000 and 2002 ETM+ images were utilized to derive brightness temperatures in order to get land surface temperatures after correcting for surface emissivity. Areas with higher temperature were extracted and identified as heat islands. There were clearly visible changes in the spatial distribution of heat islands over ten years with a movement of heat island areas from southern boundary of the city towards northern boundary. Expansion of heat island areas in the centre of the city was observed as gradually with time. From 1992 to 2000 heat island areas expanded by 18% and from 2000 to 2002 by 10% of the total land area showing an alarming rate of expansion in the future. By 2002 30% of Kandy city area was identified as heat islands. The direction of expansion of heat islands is highly correlated with the direction of expansion of built-up area as presented in the land use maps and images of city during the period of study

[email protected]

Tel: 071-7399124

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202/B Influence of potting materials on nutritional composition of red onion (Allium ascalonicum L.) grown in different potting media N Suthamathy and T H Seran* Department of Crop Science, Faculty of Agriculture, Eastern University.

Onion is commercially important as a vegetable and a condiment. A nutritional analysis of onion bulbs was undertaken at the Eastern University of Sri Lanka to determine the effect of potting materials on nutritional composition of red onion (Allium ascalonicum L.) grown in different potting media. Potting materials used in this study for media preparation were sandy soil, cattle manure, coir dust and paddy husk ash. Four treatments with five replicates were arranged in a Complete Randomized Design. Treatments consisted of different types of potting materials in different ratios (v/v), medium 1 (sandy soil: cattle manure at ratio of 6:2) used as control, medium 2 (sandy soil: cattle manure: coir dust at ratio of 6:2:1), medium 3 (sandy soil: cattle manure: paddy husk ash at ratio of 6:2:1) and medium 4 (sandy soil: cattle manure: coir dust: paddy husk ash at ratio of 12:4:1:1). Media were prepared two weeks before the planting of bulbs and filled into polybags (50 cm diameter and 25 kg capacity). Onion bulbs were planted and managed as recommendation by the Department of Agriculture of Sri Lanka. Bulbs were collected at the time of harvesting and moisture content, dry matter, ash, K and P contents of bulbs were analyzed. The results indicated that composition of potting media have significant (p 6 mm in diameter) were observed in the accessions BD/TP1, BD/ST1 and Panniyur1 while BD/MW23 and MT/RT2 also having large berries when compared to the other accessions. The highest fresh berry weight per spike (10.9 g) was observed in Panniyur1 whereas BD/MW23, BD/ST1, BD/KG38 and MT/RT2 recorded a weight of over 9 g/spike. Therefore, when considering the yield, local accessions BD/MN 41 and MT/DM7 could be recommended as the best accessions while BD/WA3, KWW10, BD/GM28, BD/MW23, BD/MW26, WGB1, BD/ST1, KWW12, MT/RT2, BD/KG38, RP/NA1, MT/RT2 and BD/TP1 can be selected for future hybridization programmes to incorporate better yield characteristics. [email protected]

Tel: 066-2222822

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207/B Morphological variation of flower buds of clove (Eugenia caryophyllus) in mid country, Sri Lanka A L S Dharmaparakrama*, I G M Rajapakshe and K R D Gunapala Research Station, Department of Export Agriculture, Matale.

Clove is an evergreen tree belongs to family Myrtaceae and its commerce is the unopened, dried, fully grown flower bud. Annual export volume of dried clove is 1972 t earning RsMn. 990 to Sri Lanka. Total clove extent is 7634 ha while 86 % is in mid country; out of which 46 % in Kandy and 26 % is in Kegalle districts. Cloves are native to the Moluccas and the first single consignment of seed has introduced to Peradeniya in 1830 and then moved to the neighboring areas. So far, no varieties of clove were identified, though some flower bud variances were observed in Sri Lanka. Therefore, different accessions of clove were collected from the mid country of Sri Lanka and studied the morphological variability of flower buds for genetic improvement activities. Collected accessions were KN/MS1, KN/MS2, KN/GL1, KN/GL2, KN/WT1, KN/WT2, KN/WL1, KN/WL2, MT/DE1, MT/AL1 and MT/DP1. Measurements were taken of the weight, length, diameter of ball and middle part of the fresh and dry flower buds while size, shape and color of the leaves were observed.

Results reveled that KN/GL2 has the longest flower buds in fresh (2.47 cm) and dry (2.19 cm) length with highest ratio (2.914) of fresh into dry length of the flower bud. Further, KN/GL2 shows the highest weights (4.84 g in fresh and 1.29 g in dry per 10 flower buds). Conversion ratio of fresh into dry weight, KN/GL2 shows the highest (3.752) whereas KN/MS1 shows the lowest (2.409). Accessions; KN/GL2, KN/WT2 and MT/DP1 have the largest fresh flower bud ball diameter (0.64-0.69 cm). In dry flower bud ball diameter, KN/GL2 shows the largest (0.57 cm) and highest conversion ratio (2.194) of fresh into dry diameter of the flower bud ball. Accession KN/GL2 shows the highest value for both fresh (0.842) and dry (0.460) flower bud middle diameter whereas the accession KN/MS1 shows the lowest for both fresh (0.517) and dry (0.489) flower bud ball diameter as well as the lowest conversion ratio (1.057) of fresh into dry diameter. Number of flower buds per cluster shows the lowest (8-12) in KN/GL2 whereas the highest (20-22) in KN/WL1. Longest leaf length (13.27 cm) was also observed in KN/GL2. Therefore; KN/GL1, KN/WT1, MT/AL1, KN/WL2 and KN/WL1 could be identified as the accessions with short and small flower buds having good conversion ratios of fresh into dry weight while KN/WT2, MT/DE1, MT/DP1, KN/MS2 and KN/MS1 as the accessions with medium size flower buds. According to overall observations KN/GL2 could be identified as the most different accession having very large flower buds among other accessions.

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Tel: 066-2222822

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208/B A study on cocoa dieback disease in Sri Lanka I S Kumari*, R D Kodithuwakku and D P P De Silva Research Station, Department of Export Agriculture, Matale.

Cocoa (Theobroma cacao L.) is one of the most important beverage crops among Export Agricultural crops. Among the diseases of cocoa, dieback disease is reported from countries such as Australia, Africa and Cameroon. Similar disease conditions were shown by the cocoa plants (about 35 years old) found in the nursery, Research station, Department of Export Agriculture, Matale. Symptoms of the disease initiate from the outer twigs as yellowing. Damage may then extend along the whole branch, reaching the main trunk, eventually resulting in tree death. Therefore, this study was carried out in the laboratory of the Research Station, Department of Export Agriculture, Matale to find out the causative organism and to screen a suitable fungicide to control the disease. Twenty infected plant twigs were collected and about 1cm2 pieces of infected tissues were removed from disease progressive area and cultured on Potato Dextrose Agar (PDA) plates after surface sterilization with 1% Sodium hypochlorite. Most frequently isolated pathogen was identified as Botryodiplodia sp. Pathogenisity of Botryodiplodia sp. was tested by inoculating twenty unwounded and twenty wounded stems of cocoa seedlings with 5 mm discs of PDA containing Botryodiplodia sp. Twenty cocoa seedlings were kept as control without inoculating or wounding. Wounded stems of cocoa seedlings showed the disease symptoms and reisolation of Botryodiplodia sp. proved the pathogenisity of the fungus. Three fungicides Heterocyclic compound(Captan® 50%(w/w) W.P .contact fungicide) Thiophanate methyl (Topsin® 70% (w/w) W.P).and Benzimidazole (Carbendazim® 50% w/w systemic fungicides) were screened in the laboratory with a control. Botryodiplodia sp was cultured on PDA plates in concentrations of 100ppm, 250ppm and 500ppm of above fungicides. After three days of incubation period at room temperature (280C-300C) colony diameter was measured of the fungus. Results showed that Benzimidazole can control the growth of mycelia even at the smallest concentration i.e.100ppm than Heterocyclic compound and Thiophanate methyl respectively. Therefore, Benzimidazole was selected as the suitable systemic fungicide which can be sprayed on to the canopy of infected cocoa trees along with the cultural practices.

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Tel: 066-2222945

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209/B A study on leaf blight disease of arecanut (Areca catechu L.) W M R W B Wijekoon*, D P P de Silva, R D Kodithuwakku and D S Pillai Central Research Station, Department of Export Agriculture, Matale.

A new Leaf blight disease of arecanut (Areca catechu L.) was recordedfor the first time in Polonnaruwa District, Sri Lanka during February 2010. This disease was affected around 400 young and mature palms in the whole area. The initial visible symptom of the disease is brown spots on the leaf blade which gradually spread through the whole leaf which result in leaf drying. Affected inflorescences also dried at later stage. The symptoms start from mature leaves and spread from bottom whorl to the top whorl of the leaves and at severe stage of the disease, the plant will die. In this study, isolation and identification of the causal organism/s of the disease and identification of suitable control measures were attempted.

Infected leaf samples were collected and cultured initially on tap water agar medium (TWA – 2% w/v) and then sub cultured on potato dextrose agar medium (PDA). Petri plates were observed daily for the growth of mycelia. The resulted mycelia were observed under a light microscope at 10x40 magnification for identification. Pathogenicity test was done by following Koch’s postulates. Concentrations of 6.0g/L (0.48% a.i) and 2.0g/L (0.16% a.i.) Mancozeb 80% w/w and 3.5g/L (0.18% a.i) and 2.0g/L (0.10% a.i) of Captan 50% w/w fungicide suspensions were tested against the causal organism under the laboratory conditions.

Curvularia sp was identified as the causal organism of leaf blight disease of arecanut and it is confirmed by the microscopic studies together with pathogenicity test. Mancozeb @ 0.48% a.i completely inhibit the mycelium growth of Curvularia sp. Mancozeb @ 0.16% a.i (3.62mm /day mycelium growth), captan @ 0.18% a.i. (3.87mm /day mycelium growth) and captan @ 0.10% a.i (3.97mm /day mycelium growth) failed to inhibit the mycelium growth of Curvularia sp. Therefore, mancozeb @ 0.48% a.i can be recommended to control leaf blight disease of arecanut. .

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Tel: 066-2222822

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210/B Studies on modified methods for pectin precipitation in commercial production of pectin from yellow passion fruit peel (Passiflora Indica)

D U Rajawardena*, E N Wijedeera and J Gooneratne Food Technology Section, Industrial Technology Institute, Colombo 7. Pectin is a high value functional food ingredient that is widely used as a gelling agent and a stabilizer in food, beverage, pharmaceutical and biotechnology industry. Most commonly used sources of pectin are from apple pomace and citrus peel. New sources of pectin are of importance to meet the increasing demand. Extraction of pectin from passion fruit peel could offer economic advantages and create a positive environmental impact to the local food industry. This study investigates on some chemical and physical characteristics of pectin extracted from yellow passion fruit endocarp (Passiflora Indica) and on economical methods to precipitate pectin from the extracts. Pectin was extracted from passion fruit endocarp, from fresh and dried powder (40 °C for 24 h), with I M HCl (pH 1.34) at 65 °C for 2 h, and filtered. Pectin was precipitated from the filtrate using three different concentrations/solvents; such as ethyl alcohol (absolute), ethyl alcohol (96 %, commercial food grade) and isopropyl alcohol, was left to precipitate for 16 h and the effect on yield was quantified. Changes in the quality parameters; such as Degree of esterification (DE), Methoxyl content, Acetyl value, Galacturonic acid content, Equivalent weight (EW), Gel grade and setting time were quantified. The yield of pectin from fresh, concentrated and dried and milled fruit endocarp was 14.03 + 0.06, 17.5 ± 0.42 and 32 ± 2 % (on dry basis), respectively. These values are higher than reported values from other sources like apple pomace and citrus peel. Although a higher yield of pectin was obtained by precipitation with absolute ethyl alcohol (32.33 ± 0.58 %), the use of commercial grade ethyl alcohol (28.33 ± 0.58 %), was found to be more economical. The DE (%) (72.56 + 1.36 > 68.73 + 0.47) and Methoxyl content (9.78 ± 0.14 > 7.9 ± 0.40) of passion fruit pectin was higher than pectin purchased from commercial sources. Results suggest that, passion fruit pectin is a high methoxy pectin (>7%) for use in the food industry. The purity of pectin was high (84.87 ± 1.03 % galacturonic acid content) while the Acetyl value was < 1% , hence gel forming (0.81 ± 0.02). Both EW (847.63 ± 25.43 < 1307.23 ± 20.94) and gel grade (1400.05) dry matter content (15.28%) while the lowest (14.6%) was observed in CO2. Furthermore, the highest mean values for the number of tillers (46), the number of leaves per plant (161) and the number of pseudostem per plant (46) were observed in CO3 compared to others. Leaf/Stem ratio was found to be higher in CO1 and Napier grasses while it was lower in CO2 grass. However, the establishment percent was significantly higher in CO1 (84%) while it was lower in the CO3 (66.7%). Therefore, it can be concluded that the Signal grass and CO3 have a potential to cultivate in the dry zone but more extensive studies are needed in few seasons .

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Tel: 065-2240761 29


218/B Performance of Guinea grass under different fertilizer application in the Sandy regosol of the dry zone in Sri Lanka

S Lavanya, L S David, E Subalini*, and M M Mahusoon

Department of Animal Science, Faculty of Agriculture, Eastern University.

The Guinea (Panicum maximum) is a tall growing tufted perennial fodder grass with a shallow root system and has fairly drought resistant. This fodder grass is recommended for the dry zone by the Department of Animal Production and Health as this has the ability of tolerating drought. A study was conducted to evaluate the performance of Guinea grassEcotype B with the application of different livestock manure (cow dung, goat droppings and poultry litter), urea and control (without manuring) at the Livestock Farm, Eastern University, Sri Lanka. Five plots were assigned to each treatment with four replicates in Randomized Complete Block Design. The plant height, number of tillers, number of leaves and leaf/stem ratio were measured at two weeks interval. Fresh and dry weights of forage were recorded at the time of harvesting (45th day). In addition to these parameters the percentage of establishment was estimated at two weeks after planting. The data were analyzed using Statistical Analysis Software (version 6.12). The results of the study revealed that there were no significant differences among the treatments for the mean plant height. The highest mean value for the fresh yield per plant at 45 days (540.55 g) was observed in the pastures treated with cow dung followed by poultry manure and the dry matter was higher (52.1%) in the control treatment followed by goat manure. The numbers of tillers (31 tillers per plant), leaves (124 leaves per plant) and pseudostem (31 stems per plant) produced in the pasture fertilized with urea were found to be the highest. Leaf/Stem ration was found to be highest in pastures treated with cow dung. Based on the results, it could be concluded that cow dung and poultry manure can be recommended as organic manures for pastures in the dry zone of Sri Lanka.

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Tel: 065-2240761

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219/B Proximate analysis of seeds of vegetable cowpea (Vigna uniguiculata L.) fertilized with EM treated animal manure Bokashi M S N Risvani, T H Seran* and N Suthamathy Department of Crop Science, Faculty of Agriculture, Eastern University.

A proximate analysis was done at the Eastern University of Sri Lanka to study the effect of different animal manures EM-bokashi, on the quality parameter of seeds of vegetable cowpea (Vigna unguiculata L.) cv-BS-1. The pot experiment was laid out in Complete Randomized Design with five treatments and fifteen replications. The treatments included application of recommended chemical fertilizer (T1), non-fertilizer (T2), cattle manure EMbokashi (T3), goat manure EM-bokashi (T4) and poultry manure EM-bokashi (T5). Each animal manure EM-bokashi was prepared in an aerobic condition and applied at the rate of 300 g/m2 as basal and top dressing application, which were applied two weeks before planting and four weeks after planting respectively. All other agronomic practices were followed as recommended by the Department of Agriculture of Sri Lanka. At the time of harvesting, well matured pods were randomly selected from each treatment and subjected to proximate analysis. Moisture, ash, protein and crude fiber contents were were analyzed. The results revealed that the animal manures EM-bokashi have significant (p card board > Plastic > paper > glass > metal. The largest fraction of the waste consists of organic matter in all the studied samples. The highest bio degradable (short term) waste was recorded in Kuruvita Pradeshiya Sabha (81.62%). The lowest biodegradable (short term) was recorded in Kaduwela Pradeshiya Sabha (50.94%). The highest non bio degradable recycling materials were recorded in Kaduwela Pradeshiya Sabha waste stream followed by polythene (5.58%), plastics (2.29%), card board (5.1), paper (7.07%), metal (tin) (2.52%) and glass (3.70%). Lowest non bio degradable recycling materials percentage was recorded in Mathara Pradeshiya Sabha’s waste stream (1.8%). Ella Pradeshiya Sabha had the highest of non recyclables which was coming under the “others” category, 8.63%. It included cloth, leather, rubber, building materials and stone, sanitary napkins, hair and some of medical wastes. It can be directly used for landfilling. The long term biodegradable solid waste percentage ranged from 2.37% to 16.52%. The findings show that the bio degradable materials range between 50.94% 81.62% which is a good source for the compost and non biodegradable recyclable materials range between 9.90% - 27.05%. [email protected]

Tel: 0772354756 46


308/C Removal of iron from ground water using a low cost household water purification system M J M D S S Jayawardane and B C Liyanage* Department of Civil Engineering, The Open University of Sri Lanka. Every person needs at least 50 liters of water per day; however it depends on the availability of water in the particular location. Even though the earth’s 75 % area is covered by water, not all that water can be consumed directly by humans. Hence finding good consumable water is not always easy on every place on earth. Even though there is plenty of water in coastal areas, the consumtion ability of that water is very low as it gives a metallic taste. Due to unwanted substances in the water of the Ja-Ela area, there are some health related problems such as discolouration of teeth. Further, this water also keeps dark coloured patches in sanitary wares. Hence the water requires cleaning even for general use. The general public cannot afford costly water filtering systems, which require frequent maintenance. Therefore, some mechanism is needed at some point to acquire a good quality consumable water supply. This research was aimed to design a heavy duty household water filtering system that will filter the water into acceptable standards to cater for the needs in areas of high concentrations of iron in ground water. The standard water quality states that the iron concentration in a drinking water sample should be not more than 0.3 mg/l, while current situation holds 6.5 mg/l. The people still do not have pipe borne water at present. From normal filtering systems iron cannot be removed. It is essential to establish a proper low cost treatment system to remove iron from drinking water. It was found that aerating the raw water helps to reduce a considerable amount of iron in water. A multiple tray type aerator was constructed and raw water was passed through the trays changing its height between two trays. This process changes the soluble ferrous concentration into an in-soluble ferric concentration and thus sediment deposits are removed using a sand media filter. This height, and the selected parameters such as sieve size and the water flow rate were found to be optimized according to a series of tests that was conducted changing various parameters in the aerator. The optimum distance between two trays was 70 cm. When consider the sieve size, it had been shown that the aerator performs at its best when the sieve diameter is 4mm which had an iron removal efficiency of 66.67%. The cost of the aerator is approximately Rs. 4760. Treated samples were tested for water quality parameters and it proved that considerable iron amount is reduced. The treated water should pass through a filter unit for drinking purposes. The filter unit is designed using a series of sand media that will ensure the removal of unwanted particles, and therefore cleans the water from muddiness and also the in-soluble ferric concentration. [email protected]

Tel: 0777577321 47


309/C Reduction of pollutants in wastewater of cold soaking paddy at small scale rice mills in Sri Lanka T P Liyanage and B C Liyanage* Department of Civil Engineering, The Open University of Sri Lanka.

Rice is the most valuable and largely harvested grain throughout the world. The demand for rice is increasing day by day with the growth of population all over the world. However, there is severe environmental pollution of inland water bodies in Sri Lanka due to discharging of untreated wastewater of rice mills. Hot soaking and cold soaking is mainly under parboiling methods. However, the wet process is important because it produces nutrient rich rice. Wastewater with high COD (>500 mg/l) generated in soaking process of paddy directly discharges into the inland water bodies. The continuous discharge of COD is causing water pollution of surface water at alarming levels. Though there are advanced treatment methods, due to high capital and operational cost small scale millers are unable to use those methods. Therefore, it is an essential to introduce a simple treatment method for rice mill effluent for small scale mills. In this study, amount of pollutants of paddy soak water in parboiling was studied. Aerobic and anaerobic digesters were used for experimental work with different experimental conditions (batch and continuous systems). Also COD variation with the soaking time was studied and it is noted when soaking time increases, COD has increased rapidly. Both batch and continuous experiment were conducted under aerobic and anaerobic conditions after introducing a microbial source using lab scale aerobic digester and anaerobic digester. COD, DO and pH variation, with time were recorded. Average COD reduction with time at aerobic digestion was about 80%, and the final COD was around 100mg/l which is lower than the permissible level (i.e., 250mg/l) to discharge into inland water bodies. At anaerobic conditions, COD reduction at batch test within four days is about 28.9% and at continuous flow test within one day is 7.7%. The results of this study revealed that the aerobic digestion is the most suitable simple treatment method for treating the rice mill effluent to reduce the COD amount. Continuous flow system with aeration is more effective compared to the batch system, which can be easily implemented coupling with a maturation pond before discharging into the inland surface waters.

[email protected]

Tel: 0777577321 48


310/C Removal of nitrate from drinking water using a bio-sand filter M A D C Lakmali and B C Liyanage* Department of Civil Engineering, The Open University of Sri Lanka

Water is the basic need for mankind. For a healthy nation, clean water is of utmost importance. In Sri Lanka, most of the rural communities are dependent on the ground water resources, However due to extensive agricultural practices, poor sanitary disposal methods and industrial wastewater discharges, most of the groundwater sources have been polluted by nitrates. High concentration of nitrates in drinking water causes health risks such as methemoglobinemia in infants. NO3-N cannot be removed by the typical water treatment methods. Removal of NO3-N is very expensive and therefore it is necessary to introduce a low cost and easily maintenained method for removal of NO3-N from groundwater for community applications. Biological removal of NO3-N from drinking water was studied in a biofilter. In this study, a full scale model for denitrifcation was developed on the sand column to remove NO3-N from contaminated ground water. Two “bio-sand filter” experimental set-ups consisting of cylindrical PVC biological reactor with 31 cm of inner diameter and 130 cm of height and square concrete reactor with 24 cm width and 80 cm height were used. Both reactors were operated in down flow mode with river sand and sea sand to test the effectiveness of sand usage. The filtration rates have an impact on NO3-N removal through the bio-film introduced at 10 cm depth from the surface of the reactors. Biofilter was designed for two phases of operations with NO3-N concentrations of 15 mg/l and 30 mg/l while keeping the filtration rates varied from 0.001, 0.005, 0.008, and 0.01m/h respectively. The fatty acid was used as the sole carbon source for denitrifyers and the maximum NO3-N removal efficiency was recorded as 100% at slower filtration rate. Although when filtration rate increases, the nitrate removal efficiency decreases. However, for all filter operations NO3-N concentrations were lower than the permissible level ie.,10mg/l specified by the SLS for potable water quality. The result of comparative study with sea sand filter performance was not within expected limits. Hence the innovated bio-sand filter with river sand is the best solution for removing NO3-N from ground water. That low cost innovated bio-filter constructed with available material in Sri Lanka is the best solution for the removal of NO3-N as a community base water purification system.

[email protected]

Tel: 0777577321

49


311/C A study of the general spatial orm characteristics of the urban areas of Ampara district B Z Jaheez and W S W J Fernando * .

University of Moratuwa, Department of Town and Country Planning

Urban form is dynamic in nature and changes with new developments reflecting economic, technological and transportation conditions in an increasingly competitive framework. Changes in urban form have implications for environmental sustainability, integration and cohesion and long term quality of life in and around cities. In Ampara district, some urban areas are growing rapidly in an unplanned manner and sprawling into the surrounding paddy fields. Thus, it may cause conversion and haphazard development of the natural environment. Another problem is that of inefficient use of land resulting in the expansion of horizontal development. Therefore, identifying such characteristics and finding the general form in the urban areas of Ampara can explain the reason why it happens and provide solutions to make the urban form efficient. In the regional context, investigating the general characteristics of urban spatial form in Ampara district is essential in the identification of regional policies and also will be useful in the formulation of plans by planners. This research was conducted in the urban areas of Ampara district to find out the general characteristics of its form, relevant potentials and issues. First of all, the study was conducted on the regional perspective, in the Eastern Province and environmental features, road networks, economic activities, and other relevant factors were analyzed. The physical features, the district capital and urban concentrations, institutions, networks between urban centers and historical context and structuring of Ampara were studied. As case studies three urban areas in Ampara were selected to find the general spatial form characteristics by the application of relevant spatial theories and methods. The initial field study conducted in Kalmunai indicated interesting results pertaining to Sainthamaruthu showing some distinct physical forms in terms of the selected characteristics. The findings contribute to the conceptual basis explaining the formation of urban areas in terms of the identified determinants.

[email protected]

Tel: 0716137446

50


312/C

Managing accident data and estimating emission levels on national roads using GIS S A Silva* and J M S J Bandara Department of Civil Engineering, University of Moratuwa, Moratuwa

In recent years, Sri Lanka has experienced a high growth in urban population and the number of private vehicles. Most evident feature of such a trend is urban road congestion; roads in some areas are also facing unexpectedly high traffic flow which causes a lot of time waste in transit and huge losses to the economy of the country. Moreover, the vehicle accidents rates on the roads and the air pollution have also been increasing rapidly in recent years because of that high traffic flows. To reduce the number of accidents, it is important to manage the accident data in systematic manner because it will provide the required information. This data is very important to traffic and highway engineers because it helps them to identify the unsafe locations of the roads and the reasons accidents. It is essential in road improvement projects to do the safety audits and find solution to minimize the number of accidents. Furthermore, managing the emission data and monitoring the emission level of zones also play big role in the environmental impact assessments because currently there is a high air pollution rate in the urban areas. In addition, it is also important to identify the air pollution caused by different pollutants because it will help to recognize the types of vehicles which contribute more to the air pollution. The objective of this study is to develop a model to estimate the emission level in different scenarios and manage the accident data to do the analysis. ArcGIS provides good platform to develop this model because the analysis tools in GIS can be directly used to analyze the available data. Methods used to develop this model and analysis options of that model are presented in this paper.

[email protected]

Tel:(0)38-2244234

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313/C

Performance analysis of vertical axis wind turbine: introduction of new blade profile with deflector-rudder unit

J A Sanath and B Sumith*

Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, University of Ruhuna , Hapugala , Galle

The present study deals with designing of wind turbine blades and deflector-Rudder unit for the efficiency improvement of a straight-blade vertical axis wind turbine (S-VAWT). A wind turbine blade has been designed considering the effect of lift and drag forcers acting on the blades which were obtained by the CFD simulation results. According to previous studies, it was found that the performance of the S-VAWT can be improved by means of the deflectors. Shapes and positions of the deflectors were selected to maximize the torque effect to the turbine on the relevant region. Performance of new blade profiles with deflectors is compared with that of NACA profiles. Comparison results show, new blade profile with deflector-Rudder unit has better power extraction ability than existing designs due to effective projection of the wind toward the blades by deflectors. Power coefficient of the present design can be increased up to 0.30 when the tip-speed ratio is around 1.25

[email protected]

Tel:(0)91-2245767

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314/C Effect of perimeter on flow rate and pressure reduction in a helical flow path designed for non pressure compensating drip emitters C P Gunasena1 and S Baduge*2 1

. Department of Agricultural Engineering, Faculty of Agriculture, University of Ruhuna Department of Mechanical Engineering, Faculty of Engineering, University of Ruhuna

2.

Appropriate designs of water emitters are critical to all micro irrigation systems. Commercially available emitters could be categorized into two main areas based on the discharge with respect to the operating pressure, namely, pressure compensating, and non pressure compensating emitters. Short-path emitters or flag emitters are non pressure compensating emitters which have a shorter and smaller helical water path having a laminar flow operated under very low-pressure systems with poor water distribution uniformity and tend to clog up easily. Due to these reasons, no studies have been carried out to study the effect of perimeter on flow and pressure regulations in short path emitters. Present research focuses to determine the effect of perimeter on flow rate and pressure in a helical flow path designed for non pressure compensating emitters. Two emitters were fabricated to have a free space as a flow path in between the nut and the stud. Space or the flow path was created by varying the thread angle (100, and 133 Deg) of the nut, and the thread angle of the stud (40, and 48 deg) while keeping the nut diameter (20.2 mm) and the stud diameter (19.4 mm) as constant values. Area and the length of the flow path were also kept constant for 0.30 mm2 and 1.393 m respectively. Perimeters of the flow path were measured as 3.52 mm, and 8.09 mm respectively with reference to the nut and stud angles. Centrifugal pump with a bypass valve was used to apply three different pressure levels (0.5, 1, 1.5 bar). Flow rate of emitters was measured for 1 minute duration using a measuring cylinder and a stopwatch. A filter was used to control the water quality received by emitters. Emitters were tested, one at a time with four replicates for each pressure level. Experimental data verification was done by comparing experimental discharge values with theoretical discharge values computed using Hazen-Williams and Manning equations. Results revealed that there is a positive correlation of flow and pressure reduction with the perimeter of the flow path. Emitter which has the highest perimeter 8.097mm showed higher reduction of flow compared to the emitter having perimeter of 3.526mm. Hazen-Williams and Manning equations over predicted the experimental results. Therefore it can be concluded that, flow rate could be controlled by changing the perimeter of the flow path and further experimental investigations are needed.

[email protected]

Tel: (0)91-2245767 53


315/C

Investigations on nearshore wave climate and coastal sediment transport: Southwest coast of Sri Lanka

I Wijayawardane, M Ansaf and H Ratnasooriya*

Department of Civil Engineering, University of Moratuwa, Moratuwa

Understanding of nearshore wave climate and sediment transport behaviour is vital for planning of coastal zone developments in an island like Sri Lanka. In this study, nearshore wave condition was investigated and the sediment transport trends were assessed for the southwest coast of Sri Lanka. Long term offshore wave data were used in establishing nearshore wave climate, with the wave transformations carried out using the MIKE 21 computer model. Based on nearshore wave climate established, empirical formulations were used to assess the sediment transport trends in the region. It was observed that the coastal sediment transportation in the southwest region occurs mainly due to the waves approaching the shore, mostly from the directional sector of 1900-2400, with the waves driving sediment northwards most of the year. For comparative purposes, field measurements were also carried out at selected locations to estimate the erosion/accretion resulting from sediment transport trends in the region.

[email protected]

Tel: (0)11- 2650567 54


316/C Tsunami impact mitigation by coastal vegetation: steady flow resistance C Manawasekara, H Thalagala and H Ratnasooriya* Department of Civil Engineering, University of Moratuwa, Katubedda, Moratuwa

In the aftermath of the Indian Ocean Tsunami (IOT), the protection offered by coastal vegetation became evident in many countries affected, and the role of coastal green belts in mitigating tsunami impacts has now been clearly recognized. In order to assess the effectiveness of coastal vegetation in tsunami impact mitigation, experimental studies were carried out to investigate the energy dissipation characteristics of the flow through vegetation. The impact mitigation by vegetation is caused by the forces resisting the flow which would depend on the individual plant characteristics as well as the overall characteristics of the green belt. A variety of vegetation exists along the coastline of the country and three distinct components of a plant structure, namely, aerial root system, near vertical stem and the branch structure, which may offer varying degree of resistance, can be identified. A coastal green belt can be characterized by its location, extent, density, pattern and the type of plants. Small scale physical model tests were carried out in a hydraulic flume in which the coastal vegetation was represented by geometrically similar models. The tests were limited to the modeling of inundation of the stem of plants without aerial roots. Water was allowed flow at a steady rate through vegetation models and energy dissipation was estimated due to the presence of vegetation. The effectiveness of coastal green belts was assessed by the percentage energy reduction for various forms of vegetation. Reduction levels in the range of 3.8 to 28.1% were obtained in the experiments indicating the possibility of achieving significant levels of energy reduction of tsunami inundation by coastal green belts. In spite of the restrictions imposed by the small scale used in the tests and the limited range of flow and vegetation conditions simulated, the results are expected to provide useful guidance on the effective use of coastal green belts as a possible tsunami impact mitigation measure.

[email protected]

Tel: (0)11-0 2650567

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317/C Assessment of exposure of Sri Lanka to Tsunami hazards from Sunda Trench: A case study of Southern coast K De Silva and H Ratnasooriya* Department of Civil Engineering, University of Moratuwa, Moratuwa

A study on assessing the exposure of Sri Lankan coastal regions to Tsunami hazards is presented in this paper. Considering the geographical location of Sri Lanka relative to the undersea earthquake prone regions in the world, it is evident that Sri Lanka is exposed to tsunamis which also became apparent by the Indian Ocean Tsunami (IOT) in 2004 and subsequent alerts in 2005 and 2007. Due to IOT, more than two thirds of the coastline in Sri Lanka in the northern, eastern, southern as well as relatively sheltered western coastal areas were subjected to inundation. However, it was clear in the aftermath of the IOT, that the degree of damage along the coastal belt of Sri Lanka was not uniform with some areas suffering more damage while in certain other areas, often not far away, there was less damage or no damage at all. The level of exposure of coastal areas exhibited a considerable variation even along a short stretch of the shoreline. Thus, it will be important to assess the risk of future potential tsunamis for Sri Lanka in order to come up with an accurate and reliable early warning system with information related to possible tsunami scenarios in the form of arrival time, nearshore wave height, extent of inundation, etc. This study was carried out using numerical modelling techniques and taking into consideration, the various stages of tsunamis due to undersea earthquakes; generation, deep water propagation, shallow water transformation and inundation. Attempts were made to arrange the results in a database containing information to be effectively utilized by a tsunami early warning and evacuation system. Attention was mainly focused on the southern coast of the country in this study.

Acknowledgement: Financial assistance by University of Moratuwa Senate Research Fund

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Tel: (0)11- 2650567

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Section D 401/D Detection of Rhinosporidium seeberi in humans and animals in Sri Lanka by using the polymerase chain reaction method and detection of anti rhinosporidal IgG in domestic animals and humans in Sri Lanka. S D T G Sudasinghe, A T Bandara, N A N D Perera, R P V J Rajapakse and S N Arseculeratne Division of Parasitology, Department of Pathobiology, Faculty of Veterinary Medicine and Animal Sciences, University of Peradeniya

Rhinosporidiosis is an infective disease caused by an aquatic protozoan previously considered to be a fungus. This is a chronic granulomatous infection of the mucous membranes and usually manifests as vascular friable polyps that arise from the nasal mucosa or external structures of the eye. The etiologic agent of rhinosporidiosis is Rhinosporidium seeberi, is closely related to several protoctistan fish and amphibian pathogens. Most cases of rhinosporidiosis occur in persons from or residing in the Indian subcontinent and Sri Lanka. Animal rhinosporidiosis has not been reported from Sri Lanka. In our study cattle nasal scrapings and human patient’s samples from nasal swabs were subjected to R.Seeberi - specific PCR and in this study domesticated animals and human blood samples were subjected for dot blot ELISA. Human blood samples were collected from rhinosporidiosis infected patients and asymptomatic population. Cattle (55), Buffalo (50), Dog (60), Cat (48), Goat (36) and Horse (34) serum samples were subjected to study the anti- rhinosporidial IgG antibodies. Out of 12 cattle samples 5 samples showed positive bands and Out of 4 human patients samples 2 showed positive bands, referable to Rhinosporidium seeberi. Rhinosporidium seeberi spores were taken as positive samples. Rhinosporidiosis in animals were not recorded in Sri Lanka but in our study cattle nasal scrapings were positive for the disease. PCR products were not subjected to sequencing. Of the 36 human samples titrated to determine the sero- prevalence of the disease, 33 samples was found to be positive at a titer from 1/25. Fifty five of 63 cattle, 12/60 dog, 25/50 buffalo 24/48 cat, 24/34 horse samples were found to be positive from 1/25. The end titer of all the human and animal positive samples were also determined This study many animals showed high titres for IgG. No animal cases of rhinosporidiosis have been reported in Sri Lanka. This study showed the existence of sub clinical infection, or immunization following exposure of the animals to soil and ground water. Acknowledgements: Financial assistance by National Science Foundation Research grant (NSF/Fellow/2006/01)

Tel: (0)81-2395721 57


402/D Identification of sibling species of Anopheles culicifacies s.l. present in Sri Lanka using multiplex BCE-PCR in the CO II region of the mitochondrial DNA I N Harischandra¹, R S Dassanayake² and B G D N K De Silva¹* 1 2

Department of Zoology, Faculty of Applied Science, University of Sri Jayewardenepura Department of Chemistry, Faculty of Science, University of Colombo

Anopheles culicifacies is the primary vector of malaria in Sri Lanka and Indian subcontinent. Presence of sibling species complexes within a single species causes more complexities as a vector in terms of vector control. Sibling species show differences in vectorial capacity, insecticidal resistance, and host feeding preference. There are five sibling species provisionally designated as A, B, C, D and E in An. culicifacies complex. Therefore, precise identification becomes more critical in vector control and disease prevalence. Along with the development and sophistication of technologies, use of ovarian polytene chromosome in semi gravid females, differences in the mitotic Y-chromosome among males of 3rd or early 4th instar larvae and use of cuticular hydrocarbon profiles are now outdated as the methods are inconvenienced. DNA based, PCR associated techniques provide more reliable answers in such studies than any of previous methods. Wild caught mosquitoes collected from malaria endemic areas (Monaragala, Kataragama and Kandy) of Sri Lanka were used for extract DNA. DNA from individual mosquitoes was extracted using a phenol-chloroform extraction method. A BCE-PCR was performed using 50ng of genomic DNA in PCR mixture to differentiate the sibling species on the basis of the variations in the cytochrome oxidase II subunit. PCR products were visualized by agarose gel electrophoresis in a 1.5% agarose gel. BCE- PCR assay accurately identified two sibling species B and E recorded in Sri Lanka. Presence of sibling species B was indicated by a single PCR band of 248bp. Sibling species E showed two bands of 248bp and 178bp. This banding pattern comparable with the previous study of identification of sibling species present in India. Therefore the sibling species B and E present in Sri Lanka can be identified by using this BCE-PCR assay and they are similar to the species recorded from India. In this study we came across with some variations of above observed results. There were some mosquitoes showing a single band between 100bp and 200bp in the same PCR assay. It may be due to a variation of sibling species. Further clarification of these samples is in progress.

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Tel: (0)11-2804515

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403/D Analysis of relative growth patterns and intraspecific morphological variation between two Macrobrachium rosenbergii (De Man, 1879) populations (Class: Crustacea, Family: palaemonidae) in Sri Lanka G G N Thushari and D H N Munasinghe Department of Zoology, University of Ruhuna, Matara Freshwater prawn Macrobrachium rosenbergii (De Man, 1879) is one of the most economically important crustacean species all over the world. In Sri Lanka M. rosenbergii fishery industry is based on wild populations. Therefore, it is important to gather information of wild populations of M. rosenbergii to identify their population variations. The objective of this study was to compare two wild populations of M. rosenbergii in Sri Lanka using morphological parameters. Sixty three individuals were collected from two wild populations: Negombo lagoon (31) and Walawe River estuary (32). Fifteen morphometric and two meristic parameters were selected for analysis. Using carapace length as the reference parameter (X), analysis was conducted based on the log transformed equation of Y = bXa which was predicted for the relative growth pattern for crustaceans. According to the derived slopes for each morphometric parameter, males of both populations indicated similar growth patterns for all parameters except one (Diagonal carapace length). For females, growth patterns of four parameters differ among two populations (Carapace width, first abdominal segment length, Ischium length, carpus length). These relationships were confirmed by F statistics and Pearson’s correlation coefficient (r). Estimated t values to justify significant differences between relative growth coefficients of each morphometric characters indicated that growth patterns of five morphometric characters were significantly different between two male populations while it was significantly different for four characters between the two female populations. Significant differences between two male and two female populations for morphometric parameters were justified using two sample t test. Results revealed that thirteen morphometric characters were significantly different between the two male populations. However, no significant differences were reported between two female populations. Chi square test indicated that meristic characters did not support to distinguish two populations. These basic population data are important for selecting brood stocks for aquaculture programs and constructing management plans to protect wild populations. Acknowledgements: Financial assistance by IFS research grant (A 4309-1).

[email protected]

Tel: (0)41-2222681

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404/D Cryptic diversity of the genus Rasbora (Cyprinidae) in Sri Lanka revealed by morphometric analysis K B S Gunawickrama and R G D R Jayawickrama Department of Zoology, Faculty of Science, University of Ruhuna, Matara Slight morphometric distinctions existing among several species of Rasbora in Sri Lanka demand close observations for reliable species demarcation. All striped rasboras in Sri Lanka bear some superficial similarities, thus identifying them as a single “Dandiya” species (trivial name in Sinhala) is a common practice. Recent taxonomic work named previously known Rasbora daniconius in Sri Lanka as Rasbora dandia, and described two new closely related species. The present study was carried out to reveal obscure diversity among sympatric Rasbora species using morphological differentiation of taxonomic importance, and to assess the contribution of morphometrics for characterizing striped Rasboras. A sample of striped Rasbora (n=132) was collected from a single location (Pattiyapola tank hydrologically connected to Walawe River), and data on 16 morphological characteristics were collected. The data were categorized a priori into four groups based on a single character ED (distance from posterior eye margin to dorsal fin origin). The Discriminant Function Analysis (DFA) that utilized all size-corrected variables resulted in a model function with ten significant contributors [Wilk’s lambda = 0.039, Approx. F (68, 465) = 8.75, p700 m) of the Gannoruwa mountain is the least disturbed natural forest while the mountain slopes (518670 m) are much disturbed and comprises largely of secondary vegetation. Gannoruwa forest is of much ecological and historical importance. This preliminary investigation examined the diversity and feeding habits of termites in the summit of the natural forest and the mountain slopes representing the degraded forest. Termites were examined in two belt transects, each 2 x 100 m and by random collections. They were identified using keys and descriptions for termites of the Indian sub-region and thereafter assigned to one of four feeding groups based on their taxonomy. A total of 24 species of termites were collected from the two forest types representing 11 genera, 5 subfamilies and 3 families. Of them, Odontotermes bellahunisensis, O. guptai, O. hainanensis, Dicuspiditermes obtusus and Kalotermes sp. 1 are new records for Sri Lanka and Glyptotermes ceylonicus, G. dilatatus, Neotermes kemnari, Hospitalitermes monoceros and Speculitermes sinhalensis are endemic to the island. The others recorded are Cryptotermes bengalensis, C. domesticus, O. ceylonicus, O. escherichi, O. feae, O. globicola, O. horni, Bulbitermes sp. 2, Nasutitermes sp. 1 and 4 morphospecies of Odontotermes. Nine termite species were restricted to the degraded forest and four to the natural forest, while 11 species were common to both habitats. Odontotermes included 12 species, the most speciose genus in Sri Lanka. The most abundant species were Nasutitermes sp. 1 (degraded forest) and Odontotermes sp. 5 (natural forest). Species Diversity Indices of the natural forest (H’= 2.135) and degraded forest (H’= 2.297), reflect the disturbed conditions at the lower elevation. The feeding groups represented Group I: primitive wood feeders (7 spp.); Group II: fungus growing wood feeders (12, spp.), non-fungus growing wood feeders (2 spp.) and lichen feeders (1 sp.); Group IV: true soil feeders (2 spp.). High representation of Group II termites (15 spp.) can be attributed to the availability of woody litter. Sampling gave a Species Accumulation Curve that progressively increased and reached a plateau. Acknowledgements: Research Assistantship from the University of Peradeniya

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406/D Photo-altered toxicity of carbofuran on Duttaphrynus melanostictus (Asian common toad) larvae B A D M C Jayatillake*, M R Wijesinghe and W D Ratnassoriya Department of Zoology, University of Colombo, Colombo 3 This study investigated the alteration of the toxic potential of a pesticide due to the exposure to natural solar radiation. This was tested using larvae of the Asian Common Toad, Duttaphrynus melanostictus (Schneider, 1799) and a commonly used carbamate pesticide carbofuran. In order to examine the effects of irradiation, a stock solution (1000 µgl-1) of the commercial grade carbofuran (Curaterr 3G) was exposed to natural sunlight between 1000 - 1500 hrs on a sunny day with a clear sky (with an average UV index of 10). D. melanostictus tadpoles of Gosner stages 24-25 were housed in glass tanks and exposed to three concentrations (150, 250 and 500 µgl-1) of irradiated carbofuran for four days (96 hrs), while controls with the same concentrations were conducted with the non-irradiated pesticide. The tanks were maintained in a room with no UV radiation. Each of the treatments and control were maintained in triplicate (n=56 tadpoles per treatment or control). Mortality was recorded at the end of the trial of four days whilst body length measurements and activity were recorded (in terms of swimming) on the initial and final day of the experiment. The present study revealed that toxicity of carbofuran is markedly reduced by exposure to solar radiation. The mortality of the tadpoles exposed to 250 µgl-1 of non-irradiated carbofuran at the end of the trial (55.5 %) was significantly reduced to half (25.9 %) (T = 6.05; P0.5). Considering the current malaria situation in the country, malaria is low on the differential diagnosis in a patient presenting with fever. Therefore medical practitioners should be encouraged to refer all patients for screening for malaria parasites only if they exhibit fever with the above symptoms and more especially if they are military personal who may act as a reservoir of infection. Acknowledgements: Financial assistance from the Global Fund. Grant no: SRL-102-G02M-00. *

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805/B

Effect of Dietary Garlic on Growth Performances and Blood Cholesterol Levels of Broiler Chickens T S P Jayaweera* Department of Livestock Production, Faculty of Agricultural Sciences, University of Sri Lanka.

Sabaragamuwa

Meat plays a significant role in improving the nutritional status of the people. Meat is an excellent source of high-quality and readily digestible protein. Presence of cholesterol in meat is a main factor discouraging the consumption. Therefore it is a timely need to reveal measures to produce meat with low cholesterol level as it will make meat more attractive to the people. Garlic is considered having cholesterol lowering effect. The effect of feeding garlic on growth performance and lipid profile in broilers was investigated. Fourteen days old hundred and fifty broiler chicks were randomly allocated to five dietary treatments in a complete randomized design with three replicates per treatment. A normal commercial broiler feed was used as the control diet and four test diets were formulated by incorporating garlic powder to control feed at 2, 3, 5 and 7% levels. Feed intake was unaffected by garlic. The weight gain, feed conversion efficiency and the dressing percentage were also not affected by garlic in the diet. Results suggest that dietary garlic powder up to 7% had no adverse effects on growth performance of broiler chicken. Serum total cholesterol level was lowered (p