PURSE 2006

Permanent URI for this collection

https://ir.lib.pdn.ac.lk/handle/20.500.14444/53

Browse

Now showing 1 - 11 of 11

Blood Pressure and Heart Rate Variability in response to a surgical stimulus under gueneral anesthesia among adult female patients: A preliminary report
(University of Peradeniya, Sri Lanka, 2006-11-30) Jayasinghe, E. H. K.; Dharmapal, H. L. P. S.; Kumarasiri, P. V. R.; Goonasekera, C. D. A.
Blood pressure changes and heart rate variability are due to complex interactions between external stimuli and mechanisms of cardiovascular control. While blood pressure changes strongly correlate with target organ damage; variable heart rate is a powerful predictor of arrhythmia related complications in patients surviving the acute phase of myocardial infarction. Nevertheless, reports on the assessment of systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) variations in response to a surgical stimulus under the conditions of general anaesthesia are not available in the literature. This study therefore, aims to assess changes in SBP, DBP and HR following an initial standard surgical stimulus such as skin incision, among adult, female patients during general anaesthesia. The relationship between these changes and the preoperative cardiovascular status is also analysed . Standard mercury sphygmomanometre was used to obtain blood pressure. The pulse rate was calculated manually. Baseline measurements were taken the day before surgery. Test measurements were taken in the theatre during surgery. The DBP and SBP increased between the second and fourth minute after the skin incision. However, between the fourth and eighth minute the SBP decreased whereas, the DBP increased from the fourth to the sixth minute and thereafter declined between the sixth and eighth minute. In the case of HR, an increase was observed before induction of anaesthesia as compared with baseline readings. It continued to increase even after induction and then two minutes after the skin incision it began to decrease. This trend continued and remained so for the next eight minutes, with minor variations. These observations suggest that baseline SBP and DBP are predictive of SBP and DBP changes before induction of anaesthesia and the initial eight minutes after surgical skin incision. However, baseline HR does not provide a good predictive value of HR during the initial eight minutes after surgical skin incision.
Antioxidant capacity of different types of Sri Lankan tea
(University of Peradeniya, Sri Lanka, 2006-11-30) Thilakarathna, R. M. M. S.; Nissanka, S. P.; Illeperuma, D. C. K.
Although Sri Lanka has been exporting tea mainly as black tea, antioxidant capacity was not adequately exploited for value addition to promote marketing. For exploitation, knowledge on antioxidant capacity of our made-tea, which might vary mainly with clonal characteristics, climatic conditions and manufacturing methods, is essential. This study was initiated to investigate the variation of antioxidant capacity of made-tea based on different cultivars, tea type (green or black tea), grades and the influence of seasonality (quality season vs their season). Black tea samples (100 g from each grade) were collected from Pedro and Samia Estates separately to fulfill research objectives. Commercial scale orthodox manufacturing process was practiced in the estates and manufacturing conditions were the same for all the collected black tea samples. Green tea grades were collected from Oliphant estate. Ten different black tea grades from three different cultivars (PK-2, TRI 2025 and Seedling-tea) and six green tea grades from cultivar PK-2 were obtained. To check the seasonal effects on black tea, ten different grades were collected from Nuwara Eliya (Dimbula season: December to March and off season) and Uva region (Uva season: July to September and off season). Herbal teas were purchased from Canada. The total antioxidant activity (TAA) of brewed tea samples was analyzed using DPPH method and it specifies a spectrophotometric method used in determining the antioxidant activity of tea with respect to Trolox (water soluble Vitamin E analog), by a DPPH (which is a free radical) assay. TAA of tea samples were extrapolated using a standard series and trolox® was used as the standard antioxidant. The cultivar TRI 2025 has 1.8 fold and 1.3 fold greater TAA compared to PK-2 and Seedling-tea respectively (p
Between two hegemonies: the double marginalisation of "under-class" tamil users of English
(University of Peradeniya, Sri Lanka, 2006-11-30) Williams, M.
We have come a long way from the days when Sri Lankan English was seen as a collection of errors or a "deviant" from/ incomplete form of Standard British English. While the description and analysis of Sri Lankan English by scholars like Kandiah and Parakrama, have contributed much to legitimizing this variety, it appears that the examples (lexis, syntax and discourse) are predominantly from Sinhala bilingual use. Thus, though the specificities of educated Lankan English reflect the areas of common language contact between Sinhalese and Tamils, and may therefore be appropriate to middle and upper class bilingual usage, they appear to exclude and thereby marginalize under-elass and rural Tamils. As long as the Sinhala user of English remains the 'standard-bearer' of Lankan English, there will be (and have been) negative implications on the acceptance of under-elass Tamil usage. The markers for such "non-acceptance" (or a deliberate refusal to accept) appear predominantly in one's pronunciation and varying grammatical constructions. Building on a presentation at the SLELTA Conference (2006), this paper seeks to provide examples of how the norms and standards of Lankan English, as well as vestigial Standard English value systems, tend to discriminate against, and pathologies under-class Tamil usage. In addition, it will seek to demonstrate how, in an already (ethnically) charged environment, these "errors" become more than simply markers of class and caste, but of ethnicity; and this has serious implications, in today's Sri Lankan context.
Blocides enhance the severity of parasiteiInduced abnormalities in the hourglass tree frog (Anura: Ranidae)
(University of Peradeniya, Sri Lanka, 2006-11-30) Jayawardena, U. A.; Rajakaruna, R. S.; Navaratne, A. N.; Amerasinghe, P. H.
Trematode infections and biocide exposure have been shown to cause abnormalities, growth retardation and increased mortality in the common hourglass tree frog Polypedates cruciger, under laboratory conditions. This study investigates the synergistic effect of trematode infections and biocide exposure on survival, growth and development of abnormalities in P. cruciger. Egg clutches from natural populations were reared in the laboratory and five days post-hatch tadpoles were exposed to monostome type cercariae released by the snail species Thiara scabra (Gastropoda: Prosobranchia: Thiaridae), in the presence of biocides. Four biocides, including two herbicides (glyphosate and 3, 4- dichloropropionamide) and two insecticides (chlopyrifos and dimethoate), were used at a low, ecologically accepted dosage (0.5 ppm). Each tadpole was exposed to 48 cercariae in four equal doses for four consecutive days (12 cercariae x 4 days) by placing the tadpole in a small plastic container containing 5 ml of different biocide solutions. Tadpoles were then transferred into separate glass tanks (n= 20 per treatment) containing 2 I of the respective biocide, fed with commercial fish feed and raised until metamorphosis. Survival was recorded weekly and growth and development were assessed at metamorphosis by measuring their snout-vent length, weight and the time required for fcrelimb emergence in 50% of the tadpoles (TE50) in a given treatment. Abnormalities were recorded at 10, 30 days post-hatch and at metamorphosis. The observed abnormalities were mainly; tail bending, vertebral column curvature and lumps (almost everywhere on the body). A significant decline in the survival (X²=28.014, df= 3, P < 0.000) was observed for all the treatments in the presence of both biocides and cercariae. Moreover, synergistic effect caused significant lengthening of TE 50 value (X² = 14.130, df = 3, P = 0.003) compared to all other treatments. Abnormality percentage was significantly higher (X²=24 .983 , df=3, p
A casestudy on password security evolution
(University of Peradeniya, Sri Lanka, 2006-11-30) Sandirigama, M.; Weragama, N. S
As the Internet and Mobile applications have been increasing in the recent past, the need for authentication over remote servers and telephones has become very important. The need of authentication is essential as the private data sent over the Internet have risk of being wiretapped. Existing password authentication schemes can be divided into two types, one requires only the weak password and the other must use the strong password. The main objective of this case study is to present a review on the evolution of the strong password protocols. Starting with the earliest password authentication protocols such as Lamport I, CINON and the PERM, the study comprehensively analyzes the most recent protocols such as SAS-2 and SPAPA. The newest protocol SPAPA stands for hash-based Strong Password Authentication Protocol with user Anonymity . The user's anonymity is highly required in a hostile environment as it prevents observing the user 's activity. Also, the SPAPA protocol is very simple and contains only hash functions and XOR operations as compared to the earlier versions, which are suitable for power and computation constrained smart card applications. The SPAPA protocol is tested and verified to be secure from Stolen Smart Card or Online Guessing Attack, Offline Guessing Attack, Stolen Verifier Attack, Replay Attack and Denial of Service (DoS) Attack. In addition, all the attacks performed on each of these protocols are covered in this case study as well. The common pattern in evolution and the details of the attacks that compromised the security measures in each of the protocol are taken into account.
Application of Cleaner Production Concept to the faculty of Engineering of the University of Peradeniya
(University of Peradeniya, Sri Lanka, 2006-11-30) Wanigasundara, W. A. U. D.; Kalpage, C. S.
This study was carried out to identify cleaner production opportunities in the Faculty of Engineering of the University of Peradeniya. The main focus of this preliminary study was laid on three areas: minimization of water use, rain water harvesting for appropriate uses and quantification of waste paper generation in the Faculty. Three male toilets in the Faculty premises were identified as key areas where most improvements can be made with regard to water wastages. Urinals which were found fitted with automatic flushing systems, activate in every 60th second irrespective of their use. It was estimated that shutting down of the water supply to urinals during off peak hours (weekends and from 8 pm to 6 am during week days), approximately 52% of the current water cost for toilets (amounts to about Rs. 152,280 per year) can be saved. Further, it was estimated that the replacement of National Water Supply and Drainage Board water used in toilets by rain water harvested from the perception on near by buildings, up to 100% of the estimated toilet water cost could be saved. A complete rain water harvesting system for the Faculty wasdesigned. The total cost of the rain water harvesting system is about Rs. 300,000 but the pay back period is only 1.8 years. Total waste paper collection by 7 Departments and 8 Administrative and Supportive Units in the Faculty was estimated to be 3.1 metric tons per year (MT/year). Segregation and collection of paper waste at the point of generation and selling them to paper recyclers would yield an annual income of about Rs. 55,OOO to the Faculty. Recycling of paper would also reduce the volume of solid waste handling at the disposal site by 3.5 m3/year.
Application on a new stochastic restricted Liu estimator in linear regression model
(University of Peradeniya, Sri Lanka, 2006-11-30) Hubert, M. H.; Wijekoon, P.
Often a researcher may find auxiliary information or prior information in addition to the sample, which can be either exact or stochastic about the unknown parameter. Therefore in the presence of stochastic prior information, in addition to the sample, Theil and Goldberger (1961) introduced a mixed estimation procedure for estimating the parameter vector in the linear regression model. However, in the presence of multicollinearity among regressor variables it was noted that Mixed Regression Estimators (MRE) are unstable and give misleading information, To overcome the problems related to multicollinearity Hoerl and Kennard (1970) introduced the use of ridge type biased estimator, and several other statisticians were developed it further. However a major improvement of this method was done by Liu Kejian (1993), and he suggested the Liu estimation procedure for least squares estimation. Recently Hubert and Wijekoon (2004) extended Liu estimation procedure for mixed regression estimation by defining a new estimator called Stochastic Restricted Liu Estimator (SRLE), and shown that SRLE outperforms the other alternative estimators under certain conditions with respect to the mean squared error matrix criterion. In this study estimators were compared using scalar mean squared error, and validity of the theoretical findings was shown by using a well known numerical example named "Portland cement", which was widely analyzed to make comparisons of estimators in the literature. This data set of "Portland cement" comes from an experimental investigation of the heat evolved during the setting and hardening of Portland cements of varied composition and the dependence of this heat on the percentages of four compounds in the clinkers from which the cement was produced. The four compounds considered are tricalcium aluminate, tricalcium silicate, tetracalcium aluminoferrite and β-dicalciurn silicate which are denoted by X1, X2, X3, and X4, respectively. The heat evolved after 180 days of curing is denoted by Y, is measured in calories per gram of cement. Using these variables the stochastic properties of Stochastic Restricted Liu Estimator are analyzed and the superiority condition over the other alternative estimators are examined.
Antibacterial susceptibility testing of catechin fraction of Tea Flush (Cultivar TRI2025) against Methicillin Resistants Staphyolococcus aureus
(University of Peradeniya, Sri Lanka, 2006-11-30) Kumbukgolla, W. W.; Bandara, B. M. R.; Kumar, N. S.; Ekanayake, E. W. M. A.; Thevanesam, V.
Methicillin-resistant Staphylococcus aureus (MRSA) has become a common cause of nosocomial or community based infections (blood stream infections, surgical wound infections, skin and soft tissue infections). The therapeutic options for MRSA infections are very limited because most MRSA strains are resistant to β-lactams, macrolides, aminoglycosides, and fluoroquinolones. The emergence of MRSA strains with reduced susceptibility to vancomycin suggests that MRSA may eventually become fully resistant to vancomycin. Therefore, new chemotherapeutic agents and new approaches are urgently needed to combat such antibiotic-resistant bacteria. Catechins are one of the major components of tea extract which show antibacterial and strong antioxidant activity. The usefulness of tea catechins in controlling methicillin resistant Staphylococcus aureus was studied using a wide range of MRSA strains. Staphylococcus aureus strains, isolated from patients in Peradeniya Teaching Hospital, which were available in the Department of Microbiology culture collection were used for the study. The purity of the sub-cultures was confirmed by selecting a single colony and checking identity by direct microscopic examination, coagulase test, and DNAase test. The oxacillin resistant strains of S. aureus were selected using the BSAC disk diffusion method. The oxacillin containing disks (10 μg) were placed on the MHA medium which was inoculated with S. aureus and incubated for 24 hours. The cultures without a clear zone around the disks were taken as resistant strains. The degree of the resistance was assessed by determining the minimum inhibitory concentration (MlC) values of oxacillin corresponding to each strain using agar plate dilution method. Eighty five strains were found to be highly resistant to oxacillin having MIC values over 128 ppm and 15 strains had MIC values in the range of 4- 128 ppm. The tea shoots of the tea cultivar TRI2025 were collected from the Tea Research Institute sub-station at Hantane, Kandy. The crude tea extract was obtained from the tea shoots by boiling with 70% aqueous methanol, and the methanolic solution was partitioned with dichloromethane followed by ethyl acetate. The ethyl acetate fraction was concentrated and freeze-dried to obtain the crude tea extract as a brownish solid . The crude extract was examined for antibacterial activity using 24 highly resistant MRSA strains. MIC values were then determined using the agar plate dilution method. Six MRSA strains showed an MIC value of 32 ppm, eight strains – 64 ppm, nine strains – 128 ppm, and one strain more than 128 ppm indicating that the tea extract is more effective than oxacillin against 23 MRSA strains. The crude tea catechin extract was fractionated by high speed counter current chromatography (HSCCC) with a view to isolating the active component. Financial assistance by the National Science Foundation, Research Grant No. RG/2005/FR/06 is acknowledged.
Candida in oral lichen planus: a histopathological analysis
(University of Peradeniya, Sri Lanka, 2006-11-30) Jayasooriya, P. R.; Tennakoon, P. B.; Amaratunge, E. A. P. D.
Oral lichen planus (OLP) is a chronic inflammatory disorder of unknown etiology and Candida species are common fungal organisms that live as commensals in the oral cavity. Although the yeast forms of Candida are non-pathogenic, hyphal forms have been implicated in the etiology of several disease processes. Evaluation of scientific literature regarding colonization of Candida species in OLP revealed controversial results. Therefore, the aim of the study was to evaluate the prevalence of Candida histopathologically in OLP lesions and to correlate the presence of Candida with the clinical form of the disease. Sixty five formalin fixed paraffin embedded histopathologically confirmed OLP samples were used for the study. Paraffin embedded blocks were prepared from incisional biopsies obtained prior to treatment with steroids. In addition, fifteen previously diagnosed Frictional keratosis tissue blocks were used as the control. Clinical features such as age, gender and type of lesion (reticular, plaque like or erosive) were obtained from the request forms while only OLP and Frictional keratosis lesions involving buccal mucosa were analyzed in the present study to avoid bias. From each block 4µm thick tissue sections were stained with Diastase resistant periodic acid Schiff (D-PAS) stain to evaluate the presence of candidal hyphae invading in to the superficial epithelium of OLP lesions. The results revealed histopathological evidence of Candida in 26% (17/65) of OLP and in 0% (0/15) Frictional keratosis lesions. This finding was statistically significant when analyzed by Chi-square test at 5% level. The mean age of OLP patients with and without candidal infection was 41.4 and 42.7 years respectively. Forty seven percent and 41% of OLP lesions with and without candidal infection were present in males while the remaining lesions were present in females. As such no statistically significant differences could be established between age/gender and candidal carriage in OLP lesions. Forty two percent, 31% and 26% of erosive, plaque like and reticular OLP lesions showed superficial candidal infection respectively. Although not statistically significant Candida was more frequently found in erosive form compared to plaque like or reticular OLP lesions. In conclusion, even though candidal hyphae have been identified in 26% of OLP lesions, it is not adequate to establish an etiological role of Candida in OLP as the presence of Candida can also be attributed to secondary infection. However, as the hyphal forms are pathogenic, in Candida positive OLP patients, addition of antifungal medication may provide beneficial results
Buddidst affiliation at Sigiriya
(University of Peradeniya, Sri Lanka, 2006-11-30) Somathilake, Mahinda
According to the Brahmi inscriptions on the western side of Sigiriya, it is obvious that there was a population of monks at the foot of the rock as early as first or second century BC. But Sigiriya came to be better known during the reign of the parricide king Kassapa who shifted his capital from Anuradhapura to Sigiriya. Moggallana I, the successor, having regained the throne once again shifted his capital to Anuradhapura and the palace on the rock of Sigiriya was converted into a monastery and offered to the Buddhist monks. The Buddhist order itself had no great love for the place; for it is not mentioned afterwards as having had anything to do with religion though the chronicle states that the Pabbatavihara built by Moggallana was granted to Mahanama thero. Although it is not possible to say precisely how long these later monasteries continued to exist in Sigiriya, there is no doubt that these monasteries continued to function even during subsequent periods, since one inscription from Abhayagiriya most probably belonging to the tenth century AD mentions Sihagiri maha sä. This is further substantiated by the fact that the recent excavations at Sigiriya have also revealed a series of developments extending from the third and second centuries BC to the twelfth and thirteenth centuries AD at the site. Besides, periodic extensions of drip-ledges and deepening of rock shelters, successive layers of plaster and paintings and at least five or six re-constructions of the walled extensions and the internal partitions indicate that Sigiriya had been used even in later times. In addition to the paintings on the main rock, a number of caves at the foot of the rock also contained paintings. Some of these caves carry several layers of paintings on the canopies and it is quite possible that the bottom layers of paintings on these are contemporary with the time when religious recluses first made their abode in the caves. The ceiling paintings at the Cobra-hood cave at Sigiriya proves that the cave was used as a Buddhist shrine and the Asana cave also contains painted fragment of a scene of which one panel depicts a worshipping scene. These figures in the cave strongly suggest that an image of the Buddha was placed on the existing throne. It seems that their fragmentary nature and unusually dramatic location have led to the Sigiriya paintings being interpreted in a number of ways. It is also evident that these expressions of various interpretations are mainly due to the lack of information. Accordingly, considerable speculation has helped to advance a few major theories in the attempt to find a solution. Of these, the most popular one that prevails at present is that these paintings depict some apsaras. It is not only the simplest but also the most logical and acceptable interpretation, especially since they are shown among and half hidden by clouds in the sky. It is believed that they depict some goddesses from Tusita heaven and it signifies Buddhist ideology to a great extent. It is thus obvious that except for a short reign of Kassapa who created secular buildings there, the Buddhist religious nature, would have been predominant in the Sigiriya area for a very long period. All these facts silently reveal a very close Buddhist affiliation at the site.
Adsorption of Cu(II) from aqueous medium on fired brick particles
(University of Peradeniya, Sri Lanka, 2016-11-30) Priyantha, N.; Kameeland, F. R.; Gunathillaka, P.
Removal of heavy metals such as copper from aqueous solutions is necessary because of their frequent appearance in waste water. Use of environmentally friendly and readily . available substances for this purpose is therefore a current need. The work reported here deals with investigation on the use of locally available fired brick particles, based on its excellent metal sorptive properties, for the removal of Cu(II) from aqueous solution, as an alternative to existing chemical treatments. Treatment of aqueous Cu(lI) solutions with fired brick particles having diameters of 1- 2 mm at ambient temperature and pressure indicates high rates of adsorption according to atomic absorption measurements. Although equilibrium is reached quickly and strong irreversible adsorption of Cu(II) is favoured at low concentrations of Cu(II) (e.g., 5.0 ppm), it takes longer time to reach adsorption/desorptionequilibrium at higher concentrations (e.g., 20 ppm). The percent removal increases up to more than 90% in neutral or basic solutions and then levels off under the experimental conditions and parameters used in this investigation. However, the saturation limit of the percent removal depends on the dose of the adsorbent as expected. Extent of adsorption at different initial concentrations of Cu(II) solutions fit both the Langmuir and Fruendlich isotherm models suggesting monolayer coverage followed by possible ion exchange. Continuous increase in the amount of the Cu(lI) adsorbed per unit mass of adsorbent support the suggestion of ion exchange of Cu(II) ions with those having lower affinity within the brick matrix such as Mg ions. Further, desorption studies indicate the strong irreversible adsorption of Cu(II) ions on brick, and consequently, this investigation would open up a new avenue of using fired brick particles, an industrial byproduct, which would otherwise be wasted with no value addition.

Browse

Browsing PURSE 2006 by Issue Date

Results Per Page

Sort Options