PURSE 2001

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Graphs, designs and difference sets
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Jayasinghe, J. A. D.; Perera, A. A. I.
Combinatorics is the branch of Mathematics, which deals with the problems of selecting and arranging objects in accordance with certain specified rules. In particular, a combinatorial design is a way of choosing, from a given finite set, a collection of subsets with given properties. The study of design was begun by Euler in 1782. While the first major result on the theory of block designs was due to Fisher in 1926. A (v,k,λ.) difference set is a k- element subset D of a group G of order v for which the multiset {d₁d₂⁻¹ : d₁,d₂ ε D, d₁ d₂} contains each non-identity element of G exactly λ. times. When an automorphism group acts regularly on the points and blocks of a block design, there is a simple way to represent the design. As a result of this action, this design correspond to difference sets and the correspondence between designs and difference sets is well known. We have observed that complete graphs can be used to construct difference sets. The equivalence of complete graphs, designs and difference sets is established by the following theorem. Theorem 1: Let G be a finite cyclic group of order n² +n + 1; n ≥ 2, and let D be a subset of G with n +1 elements. Then the following statements are equivalent: (i). There is a complete graph of order n² +n +1 (ii). There is a ( n² +n +1, n +1, 1) - square design such that G acts regularly as an automorphism group. (iii). D is a difference set with parameters (n² + n +1, n +1, 1) This result is illustrated by means of several examples. Moreover, we have proved on Theorem 2 that this result can be generalized to regular graphs. Theorem2: Let G be a finite cyclic group of order v and let D be a subset of G with k elements. Then the following statements are equivalent: (i) There is a λ (v -1)-regular graph of order v, (ii) There is a (v,k,λ.) -square design such that G acts regularly as an automorphism group. (iii) D is a difference set with parameters (v,k,λ.). These combinatorial designs and difference sets are all used for construction of codes and sequences in digital communication systems.
Greeka Ha Roma Lekhena
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Peris, M; Ponnamperuma, D. R.
The intention with which this work was undertaken is to give the Sinhala reader, ignorant of English, not to mention Greek and Latin, some idea of the diversity and quality of the classical literatures of Greece and Rome. These excerpts are not overlong, taking 10 to 15 minutes each for reading and spread over a period of seven centuries - from 5ᵗʰ century BC to the 2ⁿᵈ century AD. Among the authors selected for this presentation are historians, pleaders, dramatists, philosophers and sages. Among the subjects they deal with are accounts of travels, treatises on health, character studies, myths, fantastic happenings and legal disputes involving adultery, murder and assault and battery. Notable among these are Herodotus' descriptions of the pyramids and the practice of mummification, Thucydides on the plague of Athens, the dipocratic oath, three character studies of Theophrastus and Pliny's accounts of ghosts and eruption of the Vesuvius in which his uncle, the elder Pliny died, Aristophanes on the nature of Love, Tacitus on the murder of Agrippina and Suetonius on the murder of Julius Caesar. The translations were done from the original Greek and Latin of the authors by me into english (then published with assistance from a research grant from this University) and hereafter, now, into Sinhala by me with assistance from D.R. Ponnamperuma. The Sinhala translations also keep very close to the original Greek and Latin and may be cited without apprehension by those who resort to them. Difficulties encountered in the main were with the endering of proper names, of many of which nobody can be sure of the original pronunciation. This work is a good display of the facility of translating classical works into the asha. It also is an enticement to the Sri Lankan readership to undertake more and more in Classical works for the wide range of literature and information of the ancient world which they hold out to both scholars and the lay readership. The author hopes to bring out other and similar works from the Classics from time to me and thank the University of Peradeniya for the help he has received by way of generous search grants for this and earlier projects which have resulted in the dissemination of acknowledge, so valuable a function of an University such as ours.
Green productivity based waste minimization strategies in Sri Lankan hotel industry
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Perera, T. F. N.
The coastal areas of the country are the most favorable for the hotel industry for a number of reasons, as a large number of tourist hotels have been established in the western, southwestern and southern coastal areas of Sri Lanka. They are placed in different star classes according to the facilities offered. Irrespective of the resources, consumption of a tourist hotel is comparably higher than that for other service industries. In view of the increase in the number of hotels, resource limitations, waste generation and the negative effect on highly sensitive coastal environment, regulatory authorities in Sri Lanka have decided to enforce stringent environmental regulations on the hotel industry. Given the strict conditions relating to environmental protection and the economic strains due to high competition and costs, hoteliers are considering profitability increasing strategies. Following the Ecologically Sustainable Industrial Development (ESID) concept based on Green Productivity strategies a few tourist hotels were studied to evaluate their waste generation levels. Two such hotels located on the western and southwestern coast were subjected to waste audits based on Green Productivity principles. The main focus was on energy, water and other material utilization levels and the corresponding waste generation levels. Following the waste audit, a selection of waste minimization strategy options was considered including; • Electrical energy saving by modifying the lighting system and load reduction; substitution of solar energy for water heating; Thermal load reduction in HVAC system and demand management • Water consumption level reduction through simple consumption reducing strategies • Reusing of gray water at different and suitable needs. • Reusing and recycling of material, Procurement system administration. Beside these a large number of simple strategies were also proposed by the hotel employees. The strategies were grouped according to the investment involved as no/low cost, medium cost and high cost investments. A cost benefit analysis was carried out and most of the strategies were implemented successfully, to reduce the impact on environment while increasing the profitability of the organization. Visible economical benefits achieved through GP principles were; • a reduction in electrical energy consumption by 10 - 20% • a saving in thermal energy sources by 5 - 10% • saving in water consumption by 15 - 20%
Evaluation of two invasive plant species (Lantana Camara L. and WedellaTrilobata L.) for selected heavy metal Ion uptake from polluted areas
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Dissanayake, U. S.; Tennakoon, K. U.; Priyantha, H. M. N. D.
Heavy metals significantly contribute to the pollution of a range of ecosystems in Sri Lanka. This study examined the potential of two alien invasive plant species Wedelia trilobata L. and Lantana camara L., threatening the native flora of Sri Lanka, for the removal of nine selected heavy metal ions (Cd, Cr, Cu, Co, Ni, Pb, Fe, Mn and Zn) from polluted environments. The extent of removal of heavy metal ions by L. camara was determined by placing finely ground stems under static condition (immersing in each metal ion solution) and dynamic condition (passing each metal ion solution through a column packed with finely ground stems). In order to determine the instantaneous heavy metal uptake level, each metal ion solution was passed through fresh wood segments of L. camara. The reference plant for L. camara was Albizia odoratissima L. The other species, W. trilobata was used to investigate the efficiency of heavy metal uptake directly from polluted environments/disposal areas, with reference to Ipomoea aquatica Forsk. Under static condition, L. camara and A. odoratissima showed the ability of removing nearly 50% of Zn⁺², Cd⁺², Ni⁺²,Mn⁺²,Co⁺² and Cu⁺². However, the removal of Cr⁺⁶,Fe⁺²/Fe⁺³ and Pb⁺² was less than 50%. The removal ability for each metal ion can be enhanced under dynamic conditions and when solutions were passed through fresh stem segments. W. trilohata showed the ability of absorbing more than 1mg dm⁻³ of Ni⁺²,Mn⁺²,Co⁺², and Fe⁺²/Fe⁺³ after 72 hours and Zn⁺²,Pb⁺² and Cr⁺⁶ after 120 hours of treatment with heavy metal ion solutions. The ability of high level of ion uptake by W. trilohata, A. odoratissima and L. camara has been due to the presence of large mass of parenchyma in their tissues. This aspect has already been studied. Both study species show capabilities of heavy metal accumulation very much similar to their respective reference plants. Hence, both these invasive species can be recommended as phytoremediators to treat heavy metal contaminated industrial waste. On the other hand, the use of L. camara and W. trilobata for the control of environmental pollution may indirectly help to minimize the spread of these alien invasive species into natural vegetations.
Floristic composition and numeric abundance of weeds in the University experimetnal station, Dodangolla
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Marambe, B.; Thattil, R. O.
The University Experimental Station at Dodangolla, located ill the mid country intermediate zone (1M3), covers an extent of 83 ha of which 72 ha are allocated for crop production. Of this area 70% is utilized for perennial crop production and the rest for annual crop production. Weeds are a major constraint to crop production in all agro-ecosystems. Knowledge on the diversity of weed flora under different cropping systems and cropping seasons is important in designing judicious weed management practices. Thus, a survey was conducted as the first step of a long-term study in identifying the diversity of weed flora in selected crop production systems at the University Experimental Station. In the present study, the area under annual crop production was excluded as these fields had been continuously subjected to various fertilizer and agrochemical applications, resulting in a temporary shift in weed flora. All the perennial cropping systems with no fertilizer or agrochemical application during the past 6 months were considered for the survey during yala (2000) and maha (2000/200 I) seasons. Stratified random sampling techniques were used for data collection. Thirty-six perennial crop production models were identified at the University Experimental Station In all the surveyed perennial cropping systems, 56 species of weeds were identified of which 52% (29 species) were from family Poaceae, 22% (12 species) were from family Asteraceae, and 8% (5 species) were from family Cyperaceae The remaining was distributed among other plant families. Seventy two per cent of total weed flora was perennial species with Panicum maximum (Guinea Grass) and Pennisetum polystachyon (Yellow foxtail) dominating majority of the fields Perennial grasses dominated under Jpil-ipil, Teak, Jak and Coffee while annual broadleaves dominated the rest of the monocrop cultivations. Perennial grasses also dominated in a majority of the mixed cropping systems while annual broadleaves were dominant in Coffee+Coconut+Banana and Guava+Banana systems. However, in majority of the systems, the relative abundance of the perennial grasses was lower than that of the non-crop land, except in two perennial crop situations where the crop canopy allowed more light penetration than the others. In the present study, the impact of the mono and mixed cropping situations on the weed composition was not clearly evident. The experimental station experienced a severe drought during the study period resulting in no significant change in the composition of weed flora during the two seasons. The diversity of weeds varied widely with the cropping situation, even among the perennial crops. Pauicum maximum was the dominant grass species irrespective of the cropping situation indicating the ability of this species to survive under different environmental conditions. Surveys will be continued in three-year cycles in order to identify the shift in weed flora and to understand the changes in floral biodiversity under perennial cropping systems in the University Experimental Station.
Evalution of performance of contractors in the Road Construction Industry
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Wijekoon, S.B.
Construction industry contributes a significant. portion to the Gross Domestic Product (GDP) in any Country and its contribution to the GDP in Sri Lanka is around 6%. Traditional Construction Industry consists of Clients, Consultants, Contractors and Sub- Contractors. Contractors play a major role in this task and in order to obtain the optimum benefit from the project, they are expected to perform to a reasonable standard. The Construction Contractors in the industry are facing various challenges in performing their jobs. The Contractors' performance depends on how these challenges are faced by them during the construction stage. This study is aimed at the Road Construction Industry in Sri Lanka since there have been criticisms and complains over the contractors' performance in various forums during the past few years. Forty contractors attached to the construction industry were selected for the study. A questionnaire survey was carried out initially and only sixteen contractors responded. Some of the contractors, who responded were interviewed. General information of the Contractor Organizations, Information on completed projects, Financial background, problems encountered during the project and other relevant information were collected. Numbers of Problems faced by the contractors have been recorded and various parties responsible for these problems were also identified. Conclusions were made based on the information collected and suggestions to improve the Contractors' Performance are addressed.
Geochemistry of waste effluents from vehicle service
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Jayasingha, J. P.; Senarathne, A.
In the transportation of passengers and goods, automobiles playa major role. With the increasing population, the demand for vehicles, roads and highways has also increased. Vehicles release contaminant emissions while in motion and some of them are deposited on their bodies. When vehicles are serviced in stations, these contaminants can be collected for investigations. Under the present study, seven such stations have been monitored from where effluent samples have been collected regularly and analyzed for vital environmental parameters. Pb, Zn, Cd, Cu and Fe were the dominant trace elements found in effluents. The averages (in ppb), Pb-235.86, Zn-1802.36, Cd-6.8, Cu-23.52 and Fe -2973.67, indicate their relative abundances in effluents in vehicle service stations. The analysis further indicates that at some instances Fe, Pb, and Zn levels reach or exceed their maximum tolerance limits. High pH levels tend to fix the trace elements in clay suspensions.
Glycosylated haemoglobin (HBA1c) levels in patients with chronic periodontitis and it's ressponse to non surgical periodontal therapy.
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Galhena, B. P.; Perera, M. P.; Chandrasekara, A.
Periodontal diseases are chronic in nature, which may lead to destruction of supporting tissues of the tooth. In light of the extensive microbial plaque associated with periodontal infections, the exuberant local and systemic responses to the microbial assault and the chronic nature of the disease, it is sensible to hypothesize that these infections may influence overall health and the cause of some systemic diseases. (Research, Science & Therapy Committee of American Academy of Periodontology - 1998) A high prevalence of severe periodontal diseases was observed in diabetes subjects with complications such as retinopathy, neuropathy and nephropathy than those without complications. (Glavind et al. 1969, Rylander et al. 1986, Bacic et al. 1988, Rosenthal et al. 1988) The degree of these complications was strictly related to the degree of metabolic control of diabetes, which was assessed by the level of glycosylated haemoglobin (HbAIC) - the most accurate method to be used for this purpose (Rahlenbeck, 1998). However the converse possibility, that periodontitis predisposes or exacerbates diabetes (Tellervo Tervonen et al. 1997) has received little attention. This is a preliminary study to investigate the effect of periodontal therapy on glycosylated haemoglobin (HbAld level in otherwise healthy patients with moderate to severe adult periodontitis. The study sample consisted of fifteen subjects (mean age 42 ± 8 years) with moderate to severe adult periodontitis subjects. The level of periodontal disease and oral hygiene were assessed using probing pocket depth, bleeding on probing, number of sites with >4mm pocket depth and plaque score. All patients were subjected to non-surgical periodontal therapy without antibiotics. Patients were reevaluated for their periodontal disease conditions as well as for the level of oral hygiene using the same criteria. This was carried out ten weeks after the completion of periodontal treatment which was approximately 3-4 months from the baseline. Estimation of Glycosylated Haemoglobin (HbA₁c) levels was done at baseline and at reevaluation. Results were analyzed by using student t-test. Based on clinical parameters a significant improvement (p<0.05) was observed in periodontal disease condition after periodontal therapy. A statistically significant reduction of HbA₁c levels after therapy was observed in patients who initially exceeded the upper limit of the normal range of HbA₁c (>8% of total haemoglobin). The changes observed in patients with normal HbA₁c levels at the baseline were not statistically significant (p>0.05). This study also reveals a statistically significant correlation between improvement of probing pocket depth and reduction in glycosylated haemoglobin (HbA₁c) levels (r = 0.93).
Factors contributing on use of modern family planning methods among sinhalese married women in Hindagala
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Dissanayake, D. S.
This study was done to determine the factors such as socio-demographic, knowledge, service provision and the influence of the husband on the usage of modern family planning among married Sinhalese women. These factors were further analysed among non users, temporary method users and permanent method users of modern family planning. Finding out the unmet need of the modern family planning in limiting a child birth and to identify the reasons for non usage of modern family planning were among the objectives. A community based cross sectional study was carried out in Hindagala in the district of Kandy during the months July/August 2000. A random sample of 300 married women in the reproductive age group from clusters distributed in 22 randomly selected villages in the area were studied using an interviewer administered questionnaire. Of the respondents 61.3% were users of a modern family planning method. Most popular method was the Depot-Medroxy Progesterone Acetate (DMPA) while male sterilization was the least popular. The usage of modern family planning showed a statistically significant association with the educational level and the socio-economic level of the respondents. The mean number of living children was lowest among the non-users. Yet, the unmet need in modern family planning for limiting a childbirth was found to be high (21.3%). Differences in knowledge between the non-users, temporary method users and permanent method users regarding Oral Contraceptive Pills, DMPA, Intra Uterine Contraceptive Device (IUCD) and Ligation and Resection of Tubes were statistically significant. Among all respondents, knowledge on IUCD was inadequate while knowledge on vasectomy was very poor. Frequency of home visits by midwives had a significant bearing on the usage of modern family planning. In 37.1% of the non-users, husbands' disapproval was one of the important reasons for non-usage of a modern family planning method. Mostly disliked method by men was the IUCD. The findings imply the need to improve counselling on modern family planning.
Electrochemcial detection of superoxide radical anion
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Herath, H. M. A. M. C.; Rajapakse, R. M. G.; Wickramasinghe, A.; Karunaratne, V.
Superoxide radical anion (O2-) is a short-lived, extremely reactive species formed upon one-electron reduction of ground state triplet oxygen. O2-, in the aqueous medium abstracts a proton to produce H02 which disproportionates to give H₂O₂ and hydroxyl radicals (OU). All these species are good oxidants that can attack organic pollutants in the aquatic systems. The formation and the role of O2- in the biological systems are also of great concern in terms of the cytotoxicity of O2- towards many cellular constituents. O2- also involves in the defense against viral and bacterial attacks. Therefore, a development of a quantitative method to determine O²-in solution is very important. In this respect we have tested several quinone type compounds as mediators for the design and development of an electrochemical method for the detection of O²"-. Listed below are some of the materials we have investigated in acetonitrile. (Table) As can be seen from the above table, 1,2,3-triketohydrindene hydrate is a promising O2- quencher similar to that of l,4-benzoquinone. Detailed mechanistic studies reveal that the compound reacts immediately with O2- once formed, and therefore, acts as a mediator for the detection of O2-
Electrochemically synthesised conduting polyaniline for electronic and optical applications
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Velmurugu, Y.; Chandrakanthi, R. L. N.; Careem, M. A.
Since the discovery of the new exciting physics and chemistry of conducting polymers, it is possible to change the electrical conductivity of the polymer from insulating to highly conducting states by incorporating suitable ions into the polymer. This process is often referred to as doping. In this communication we report experimental result on doping polyaniline, one of the versatile conducting polymers. Polyaniline films were formed by electropolymerization from O.IM aniline solution in HCl, camphorsulfonic acid (HCSA), ethanedisulfonic acid (EDSA) supporting electrolytes. It has been observed that the kinetics of the electrochemical doping of polyaniline films depends on the history of the electrochemical events undergone by the film. For example, the current associated with the oxidation increases with waiting time at a given potential, indicating that longer waiting time allows for better recovery of the residual charge. In order to determine the influence of counter ions on the redox properties of polyaniline, the polymer films were prepared and cycled in solutions containing various functionalized acids. Results obtained indicate that the properties like structure, conductivity and air stability of polyaniline, depend upon the nature and extent of doping and waiting time.
Electrochemical methods for the investigation of reactivity of propanil
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Rodrigo, U.; Priyantha, N.; Jayawickrama, D.; Bandara, A.
Propanil is a common and a widely applicable herbicide that is extensively used in Sri Lanka on rice and potatoes. Colorimetry and gas chromatography have quantitatively determined its presence at 10⁻⁵ M concentration levels in soil, plant and water. Residual analysis of Propanil has been successfully conducted using gas chromatography with electron capture detector, as 3,4-dichloroaniline is the principal degraded product. Electrochemical methods are generally inexpensive and easy to perform although some skills are necessary. Consequently, electro analytical methods have been attractive for quantitative and qualitative analysis and for mechanistic studies in recent years due to their unique advantages over traditional methods. The goal of this research is to employ electrochemical methods, which provide reliable detection methodology for electroactive substances, in order to investigate the kinetics of degradation of Propanil, together with adsorption characteristics of it on glassy carbon surfaces, under different experimental conditions. The stability and hence the reactivity of Prop aniI is a function of both solution pH and time of solution preparation. Propanil is fairly stable in mixed water/ethanol medium between pH 4 and pH 7 for a period of ten weeks. However; in strong acidic medium (pH =1), it undergoes rapid degradation, while in strong basic medium (pH = 13), its degradation follows first order kinetics with an apparent rate constant of 9.2 X 10⁻⁸ S⁻¹ An adsorption characteristics of Prop aniI is also pH dependent, and it is irreversibly adsorbed onto glassy carbon surfaces in basic medium. A fresh solution of 3,4-dichloroaniline mimics the behavior of Propanil after degradation. According to cyclic voltammetric experiments, Propanil is found to be electro active under extreme pH condition such as pH 1 and pH 13, while below pH 4, interference of solvent breakdown masks its activity. The electro activity of Propanil, however, strongly depends on the solution pH and the time of solution preparation. Comparison of the electrochemical behavior of fresh solutions of 3,4-dichloroaniline and that of Propanil prepared at different time periods, and the variation of the features of voltammetric peaks of these two analytes at different pH's suggest that the principal degradation product of Prop aniI is 3,4-dichloroaniline. Although this degradation process is very rapid at pH =1, it would probably undergo slow degradation under environmental conditions. Such studies would promote the use of economical and simple electroanalytical methods for investigation of the fate of pesticides in the environment, and to design models for pesticide degradation pathways.
The English language ability of fourth year medical students and their performance in the essay component of the forensic medicine paper
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Silva, L. De; Babapulle, C. J.; Marambe, K.; Edussuriya, D.
The central issue that led to this investigation is the concern among academic staff of the Department of Forensic medicine that the average fourth year student completing the relevant MBBS examination is unable to demonstrate his/her knowledge of the discipline in a satisfactory or convincing manner in English. Literature review revealed that previous research addressing this issue had reported a significant association between English language ability and the performance in different stages of the MBBS course. The objective of this study was to find out whether there was any significant correlation between the written communicative competence in English (ELA) and performance in Forensic Medicine of fourth year medical students. The Linguistic analysis of the ELA and the performance in Forensic Medicine were evaluated independently by respective content experts on the basis of answers students had produced for selected questions in the Forensic Medicine II, April 2000 examination paper. These questions were selected on the basis that critical analysis and communicative competence were required to formulate a satisfactory answer. The study sample consisted of 177 students sitting for the examination for the first time. The gravity chart scale used to determine the ELA was based on semantic, syntactic and morphological criteria. At the lowest end of the scale, 1 and 2 were assigned to scripts that contained sentences that failed to make sense and showed a poor and weak grasp of the language. The language level of scripts categorized as 3 & 4 showed bare competence and competence in performance, respectively. Scripts classified as 5 reflected ELA categorized as good. Of the 177 scripts subjected to the analysis, 6 were classified as poor, 89 as weak, 63 as barely competent/competent and 19 as good. Despite such dismal expressions of language surprisingly 90% of the students were successful in obtaining passes in Forensic Medicine at the examination. There was no significant relationship between the ELA and the scores obtained for the essay component of the Forensic Medicine paper (X2 =2.2,P< .05 ). On the basis of what we observed it is clear that competence in English writing is not a requirement to be successful in certain questions of the essay paper that were thought to require a high degree of English language ability.
Eosinophilic host response as a prognostic variable in oral squamous cell carcinoma
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Soysa, H. N. S.; Tilakaratne, W. M.
Tissue eosinophilia in squamous cell carcinoma has long been recognized. Several studies have been carried out in the past in order to find the relationship between the amount of tumour associated eosinophils and prognosis of oral cancer. But the results of previous studies are not consistent and revealed contradicting conclusions. Therefore the objective of the present study was to compare the relationship between eosinophilic host response with histological parameters such as metastasis, pattern of invasion and level of differentiation. In addition site, age and sex were also compared with tumour associated tissue eosinophilia. The study sample consisted of 100 cases of oral squamous cell carcinoma selected from the archives of the Department of Oral Pathology of Faculty of Dental Sciences. The cases are from various sites in oral cavity. The sections, which were taken through the lesion, were histopathologically evaluated. In each case 10 high power fields under oil immersion were examined and the number of eosinophils were counted. Mean number of eosinophils at the advancing front of the lesion were analyzed with regard to other tumour characteristics such as level of differentiation, pattern of invasion and presence or absence of tumour metastasis. In addition age and sex were also compared with the amount of tissue eosinophils. Mean number of eosinophils was high in lesions without metastasis but the difference did not reach statistical significance (p>0.05). Pattern of invasion and level of differentiation seem to have no significant correlation with the eosinophilic count. Tumour associated tissue eosinophilia (TATE) was not related to tumour site, patient age or sex. In conclusion, our results suggest that tumour associated tissue eosinophilia is not a clinicopathologic ally useful prognostic marker in oral squamous cell carcinoma.
The Eastern influence on the Western thought, with special reference to Buddhist philosophy and Nietzsche
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Rajaratnam, M.
Eastern philosophical trends influenced Western thought immensely in the later modern period. This is especially evident in Kantian and Post Kantian philosophers. This study focused on Buddhist influence on NIETZSCHE (1844 - 1900) who is one of the twentieth century most important, controversial and influential philosophers. Fredrich Nietzsche is the author many philosophical works including The Birth of Tragedy (1872), untimely Meditation (1873-6), Human, All Too Human (1878-80), The Dawn (1881), The Gay Science (1882), -Spoke Zarathustra (1883-1885), Beyond Good and Evil (1886), On The Genealogy of Mora (1887), The Anti-Christ (1888), The Autobiography, Ecce Homo (1888) and other writing The main philosophical task of Nietzsche is to unmask the fictions and delusions of Europe values, in the light of a Buddhist understanding of philosophy and ethics. The main contribution of Buddhist philosophy consists of the critique of metaphysic with deep consideration of social change through meditative and existential understanding. the historians of Indian philosophy consider Buddhist philosophy, as the best form of India thinking, for its critique of metaphysics and the dialectical understanding of reality and for notion of Nihilism. The existential understanding and the value system of Buddhist thou influenced many Post Modern thinkers. Nietzsche also deals with overturning the history Western Metaphysics, European Nihilism and the Principle of new valuation of Western philosophy. Nietzsche's mission on "The will to power" is an attempt at a revaluation of values, based on an Eastern understanding of philosophy and values. Nietzsche's approach the conventional problems of Western philosophy is unique and he identifies the experience that determines his thinking. "Life ... more mysterious since the day the great liberator came over me - the thought that life should be an experiment of knowers" ( The Gay Science. 1882. Book IV no. 324). The fundamental position within which Nietzsche unfolds the guiding question 0 Western thought is deeply influenced by an understanding of eastern existential philosophy an Self-realization. The understanding of the essence of being and the practical realization 0 values have been symbolized as ' death of God' in Buddhist philosophy and Nietzsche' Thinking. In Nietzsche's discourses, Zarathustra voices the Nietzschean idea of 'over- man' which can be compared with the Buddhist 'Bodhisatva' ideal- that has come to be association with Nietzsche more than any other ideal. The doctrine of Eternal Return - being as a whole touches the fundamental thought of Nietzsche' s philosophy.
Evaluation of the herbicidal efficacy of six commonly used herbicides and their effect on photosynthesis, chlorophyll content and yield of rice(Oryza Sativa)
(Unviersity of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Bandara, D. C.; Gamage, R. S.
Rice is the staple food of Sri Lankans, and thus it is imperative that yields are optimized. It has been reported that 20-40% of rice yields are generally lost due to weed competition, which shows the urgent need for sustainable weed management. For many countries, use of herbicides is the easiest and most effective option for this purpose Therefore, this study was conducted as a field trial to evaluate I) the efficacy in controlling rice weeds among the currently used popular herbicides bispyribac sodium, propanil 360g/l, thiobencarb 400g/1 + propanil 230g/1, oxadiazon 80g/1 + propanil 230g/l, quinclorac, and fenoxa prop-p-ethyl, and 2) their effect on photosynthesis, chlorophyll content and yield of rice plant. Though bispyribac-sodium is considered as a total killer, it does not have the capability of controlling Isachne globosa even at high dosage levels Therefore, a laboratory trial was undertaken to determine the time of application and ideal dosage to control this problematic perennial grass weed. Six herbicides (at recommended doses) and a control (no chemicals) were used to study the herbicidal efficacy on controlling rice weeds in the maha season 2000/2001 in direct seeded rice fields at Hingurakgoda. Bispyribac sodium, propanil 360g/l, thiobencarb 400g/1 + propanil 200g/l, oxadiazon 80g/1 + propanil 230gil were applied at the I st time of application (7-8 DAS) whereas quinciorac and fenoxa prop-p-ethyl were applied at 2nd time of application (13-14DAS) For the laboratory trial, eleven days after the establishment of lsachne globosa cuttings, seventeen treatments of the above chemicals were carried out including the control to study the efficiency of controlling lsachne globosa. Photosynthesis and chlorophyll contents of rice flag leaf were measured at 10 weeks after sowing by means of a photosynthetic meter and spadrneter, respectively. Also yield of each plot was collected. Weed species counts at 6 weeks after sowing and weed dry biomass per stand count (g/m') were measured Controlling efficacy of treatments for the Isachne globose was assessed visually as a count at 14 days after the application. It was seen that efficacy of weed controlling increased according to quinciorac < fenoxa prop-p-ethyl < propanil 360g/1 < thiobencarb 400g/1 -\- propanil 200g/1 thiobencarb 400g/1 + propanil 200g/1 < oxadiazon 80g/1 + propanil 230g/1 < bispyribac sodium. There was no significant effect among chemicals over the physiology of the rice plant, but there was a significant negative effect from the control plot Application of bispyribac-sodium on the experimental plot resulted in a relatively high yield of 6250 Kg/ha compared to other treatments According to the laboratory trial, propanil was the major constituent of the herbicide capable of controlling Isachne globosa when applied at the stage of 10-1 1 days after planting at recommended dosage levels. This study revealed that bispyribac sodium rAcetolactate synthase inhibitor] has the potential to control other rice weeds available 111 paddy fields where control of lsachne globosa is not targeted. Application of the herbicide has to be made at an early growth stage of the weed to control lsachne globosa effectively.
Effect of foliar fertilizers on growth and yield of Tomato
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Samarasingha, G. G. De L. W.; Nandasena, K. A.; Lathiff, M. A.; Maraikar, S.
Plants absorb nutrients mainly through roots, but ability to absorb nutrients directly from leaves is also well known. Nutrient disorders, mainly micronutrient deficiencies, are often corrected by spraying leaves with the appropriate nutrient solution. Most vegetable growing farmers in Sri Lanka regularly use foliar fertilizers claiming that additional yield increases an obtainable though the Department of Agriculture (DOA) does not recommend such. The present study was conducted to evaluate the effectiveness of two foliar fertilizen namely Yogen and Maxicrop, compared to DOA recommended fertilizers on tomato (variety T 245 ) under field and greenhouse conditions. The treatment combinations were two foliar fertilizers alone, and three combinations of foliar fertilizers and DOA recommended soil applied fertilizers. The DOA recommended soil applied fertilizers served as the control. The treatment were triplicated. In the field experiment plant height and yield data were recorded and in the greenhouse experiment plant height, chlorophyll content and dry matter production were recorded. At the full bloom stage, greenhouse experiment was terminated and plant samples were analyzed for macronutrients viz N, P, K, Ca, Mg and S and for some micronutrients ( Zn, Cu and Mn) Results of the field experiment showed that there was no significant difference (P>O.05) in plant height and fruit yield due to application of foliar fertilizers compared to DOA recommended fertilizers. However, application of Yogen and Maxicrop together with DOA recommended fertilizers resulted in a yield increase of 3.4 t/ha and 0.3 t/ha respectively. However, these differences were not significant (P>0.05) which may be partially due to the initial nutrient level of soil. In the greenhouse experiment there was no significant increase (P>O.05) in plant height, chlorophyll content and dry matter percentage. However, Nand Zn contents in plant tissue increased significantly (P>O.05) when foliar fertilizers were applied as a supplement to recommended chemical fertilizers. It is recommended that extensive research should be carried out to examine yield and economic gains in using different concentration levels of Yogen and Maxicrop in different soils before making any recommendations on their application.
Effect of gibberellic acid bagging on shelf life and quality of "EMBUL" BANANA
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Ikiriwatte, C. J.; Heenkenda, H. M. S.; Karunaratne, A. M.
'Embul' is a popular cultivar of banana in the local market. However, high ripening rates, disease susceptibility and skin blemishes have limited their export potential. A preliminary investigation was carried out to determine the effects of pre-harvest treatments with gibberellic acid and bagging, individually and their combination, on postharvest quality of the bananas. Among the parameters investigated were, changes in ripening and disease susceptibility, changes in length dimensions and other physicochemical characteristics. A monoculture plantation belonging to the Department of Agriculture, Gannoruwa was used as the experimental site for this study. The treatments given in a factorial experimental set up were, spraying 100 ppm gibberellic acid (GA3), bagging (brown paper bag tied at both ends of the bunch, with a loose polythene cape, tied on top to protect the bag), combined treatment of spraying GA3 and bagging, and controls which were not given any treatment. The results generated to date demonstrated that GA3 treatment may reduce ripening rate and also reduce incidence of crown rot. There was no evidence that susceptibility to anthracnose was affected by the treatments. There was at least a 10% increase in fruit circumference, and pulp width due to bagging alone or in the combined treatment, in the unripe stage. However, after ripening this increase was observed only on pulp widths in the combined treatment. Approximately a 10% reduction of peel thickness (ripe stage) in bagging treatment and 10% increase on peel thickness (ripe stages) in GA3 treatment were observed. There was at least a 10% increase in weight in bagging treatment and a 30% increase in weight in the combined treatment. With ripening, a 40% reduction in weight loss was observed in the combined treatment whereas only a 20% reduction was observed in the individual treatments of bagging and GA3 treatments. A 10% decrease in the following parameters was observed in the unripe stage in both bagging treatment and combined treatment; firmness, titratable acidity and pH. In addition, a 10% decrease in titratable acidity and 20% decrease in soluble solids content in the unripe stage was observed due to GA3 treatment. After ripening, a 10% decrease in firmness was observed in both bagging and combination treatments, and a 20% decrease in firmness was observed in GA3 treatment. However, in the bagging and combined treatments, soluble solids content which showed a 40% reduction in the unripe stages, decreased to a 10% reduction after ripening. In addition, a 10% reduction in titratable acidity was observed in the combined treatment and GA3 treatment after ripening. In the bagging treatment a 10% decrease in pH was observed even after ripening. The GA3 treatment reduced incidence of crown rot. It also reduced the ripening rate, and contributed for shelf life improvement. Bagging treatment increased most of the length dimensions. The contribution of GA3 was low in this aspect. Of the 4 treatments, the combination of GA3 and bagging contributed to the best length dimensions. These results have to be confirmed by statistical analysis when sufficient data are available.
Effect of soil nutrients on the invasion of prosopis juliflora and opuntia dilienii at Bundala National Park
(University of Peradeniya, 2001-11) Chandrasekara, C. M. C. P.; Perera, G. A. D.; Seneviratne, P. R. G.
Prosopis juliflora and Opuntia dillenii have invaded the thorn scrub forests in the southern dry forests of Sri Lanka. This study was conducted to identify soil nutrient status that may have influenced the successful invasion of the two alien species. Soil pH and macronutrients including nitrogen, phosphorus, potassium, calcium, magnesium & sodium were examined in four 40 m diameter circular plots at Bundala National Park. Foliar nutrient contents were estimated in some selected dominant plant species and in two invasive species to compare nutrient absorption. Total nitrogen content was determined using Kjedahl method while total phosphorus content was estimated using a colorimetric method. Concentrations of potassium, calcium, magnesium and sodium were determined by atomic absorption spectrophotometer. Soil pH was determined using a pH meter. Results showed that the concentrations of potassium, calcium, magnesium and sodium in the soils of pure invasive plant stands are significantly higher than those of natural forest soil (pooled t test: p < 0, <0.004, <0, <0 respectively). Studied invasive species had high potassium and calcium contents in their foliage when they grew in places where the alkali cation concentrations were high. No differences were observed in the pH, total nitrogen and phosphorus contents between natural forest soil and soil of pure invasive plant stands. Therefore, soil pH, total Nitrogen and phosphorus may not affect the successful invasion of two alien species and the suppression of natural forest species by studied alien species. The invasion of P. juliflora and 0. dillenii in the study area is strongly influenced by the concentration of alkali cations in the soil. These species can absorb and store high potassium and calcium concentrations when they grow on soils where potassium and calcium concentrations are high. It may be one reason for their ability to grow successfully in such habitats.
Effect of Coconut , soya and gingelly oil on guinea pig lipid status
(University of Peradeniya, Peradeniya, Sri Lanka, 2001-11-16) Edirisinhe, E. M. I.; Fernando, P. H. P.; Perera, P. A. J.
A diet that is rich in saturated fat is considered atherogenic and therefore nutritionists have recommended limiting the proportion of calories derived from saturated fat, as a means of reducing the incidence of coronary atherosclerosis. According to the available health statistics of 1998, coronary heart disease is a leading cause of mortality and morbidity in the middle- aged population of Sri Lanka. Among the possible factors, high intake of coconut oil is believed to playa central role in development of coronary atherosclerosis. This belief resulted in the reduction of coconut oil use and Sri Lankans shifted to consumption of other vegetable oils in the market. The cholesterol metabolism of the guinea pigs closely resembled that of human, carrying the majority of cholesterol in the low-density lipoprotein (LOL) fraction and responds to change in the dietary fat quality, especially in the absence of dietary cholesterol. Four types of guinea pig diets were formulated to meet specific requirements with defatted coconut poonac, textured soya protein, wheat flour, paddy husk, mineral and vitamin supplements, and 5 % (w/w) fat in the form of coconut oil, soya oil, 1:1 mixtures of coconut and soya oil or gingelly oil. Four groups of male Hartly guinea pigs, 10 animals in each, weighing between 300 - 450g were assigned to one of the four diet containing above mentioned oils. After 4 weeks on the test diets, animals were bled after 14h fasting and their serum analyzed for total cholesterol and triglycerides. Results were analyzed using one-way anova and least significance test. All serum total cholesterol values were significantly different from each other. Coconut oil gave a high serum total cholesterol value of 59.4 ± 4.0 mg/dl, whilst gingelly oil gave a low serum total cholesterol value of 31.8 ± 6.8 mg/dl. The serum cholesterol level of coconut, soya mixture (1:1) and soya oil consuming animal groups was 52.8 ± 8.5 mg/dl and 38.2 ±7.3 mg/dl respectively. There was no marked difference in the mean serum triglyceride levels in the groups that were fed with different oils. When fatty acid composition of different oils are considered in relation to their effect on blood lipid status, it appears that saturated fat increase serum total cholesterol, while mono and polyunsaturated fats do not increase serum total cholesterol. The serum triglyceride level appears to have no correlation with quality of fat.

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