A determination of air pollution in Colombo and Kurunegala, Sri Lanka, using energy dispersive X-ray fluorescence spectrometry on Heterodermia speciosa

Sri Lanka is facing severe environmental problems such as air and water pollution due to rapid industrialisation and urbanisation. Because there have not been many studies on heavy metal pollution in Sri Lanka, the present study attempts to contribute to the literature a determination of metal pollution using indicators found in lichen specimens. Our study utilised energy dispersive X-ray fl uorescence spectrometry to determine element concentrations resulting from air pollution in the lichen species Heterodermia speciosa Wulfen. Th ese samples, collected from Colombo and Kurunegala, Sri Lanka, were analysed using the energy dispersive X-ray fl uorescence (EDXRF) method in order to determine the concentrations of 13 diff erent elements. A radioisotope excited X-ray fl uorescence analysis was applied to the elemental analysis of lichens using the method of multiple standard addition. Our qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, manganese, copper, zinc, lead, bromine, rubidium, strontium, yttrium, and gallium. Samples from the environment around Colombo, which is a highly congested urban area with much industrial development, were found to be more polluted when compared with Kurunegala, a city that is less congested and without industries. Concentrations of K, Ca, Ti, and Fe were always higher than other elemental concentrations in the lichens we analysed, a fact attributed to the proximity to the sea or exposed earth crustal sources. From the elements reported from the 2 cities, K, Ca, Ti, Fe, Mn, Zn, and Pb were reported at concentrations higher than background levels. Levels of Pb and Zn in samples from Colombo were higher than those from Kurunegala, refl ecting the increased vehicular traffi c. Th is study reveals that the common lichen species Heterodermia speciosa can be used as an indicator lichen to analyse the pollution level and other elements in the atmospher

A study on the extent, aetiology and associated factors of dandruff in a group of medical students and the in vitro effects of antidandruff preparations

Introduction: Dandruff is a scalp disorder, characterized by itching and rapid skin flaking of the scalp of a person. Yeasts of the genus Malassezia are responsible for dandruff. The prevalence of dandruff in South Asia is 60.1%, whereas in the world it is 50%. The objectives of this study were to ascertain the prevalence, describe associated factors, isolate Malassezia sp. from dandruff samples of medical students and test the anti-fungal effects of commercially available shampoo and crude extracts of commonly used herbs against Malassezia. Methods: Ninety five students were chosen by systematic sampling. A self-administered questionnaire was used for data collection. Samples of skin flakes/swabs was collected from the scalp of participants. Specimens were examined using three direct microscopic methods. Fungal colonies isolated on Saborauds/Dixon Agar were identified using Gram stain and catalase test. Antifungal activity of six shampoo brands and crude extracts of eleven herbs were tested against isolated Malassezia sp. by agar well/disc diffusion method. Results: Prevalence of dandruff was 64.2% in the study group. The typical ‘spaghetti and meatball’ appearance was seen in the skin flakes taken from 44 of 61 (72.1%) students. Malassezia sp. was isolated only from 49 of the 61 students (80.3%). In-vitro, anti-malassezial effect (Inhibition zone (IZ)&gt;10mm) was observed in 4 of the 7 tested ‘anti dandruff’ shampoos. Crude extracts of fresh leaves of Psidium guavava (guava), flowers of Punica grantum (pomegranate) and fruits of Solanum lycopersicum (tomato) and Citrus hystrix (Kaffir lime) showed IZs &gt; 10mm. Conclusion: Prevalence of dandruff in the studied group of medical students was higher than in the Asian population. Four of the tested ‘anti dandruff’ shampoos and crude extracts of leaves of P. guavava (guava), fruits of S. lycopersicum (tomato), C. hystrix (kaffir lime), and flowers of P. grantum (pomegranate) showed an in-vitro inhibitory effect on the growth of Malassezia sp.</p

Antimicrobial activities of selected herbs and two herbal decoctions against Methicillin Resistant Staphylococcus aureus (MRSA)

Objectives: To determine the antimicrobial activity of selected herbs against MRSA.Methods: Aqueous extracts, of dried stem bark of Pongamia pinnata (magulkaranda), dried stem of Rubia cordifolia Linn (Welmadata), tender leaves of Jasminum officinale Linn(Jasmine), dried stem of Berberis ceylanica (Daruharidra), Garcina zeylenica (Goraka) and two ayurvedic decoctions were prepared following the traditional ayurvedic practice by boiling chopped pieces of herbs in 6 volumes of water down to 1 volume to obtain neat and down to half volume to obtain double (2x) concentrations of the extract. Five clinical isolates of MRSA, were tested in triplicates using well diffusion method with cloxacillin and vancomycin as positive controls. Further minimum inhibitory concentration(MIC) of the aqueous extracts were determined using the pour plate method.Results: Garcina zeylenica had an average zone of inhibition of 13mm against MRSA. The ayurvedic preparation which consists of Dummulla, Ginger, Aralu, Bulu, Nelli, Gon Kekiri, Lunuwila, Katukarosana, dried Turmeric, Venivel and Rasakinda had a 14mm zone of inhibition, and the decoction which consisted of Venivel, Rasakinda, Jasmine, dried grapes, Asamodagam, Aralu, Bulu and Nelli, gave a 16mm zone of inhibition. Jasminum officinale, Pongamia pinnata, Rubia cordifolia Linn and Berberis ceylanica did not give a zone of inhibition. The neat concentration was the lowest concentration tested which inhibited growth of MRSA isolates in all three extracts.Conclusions: Aqueous extracts of Garcina zeylenica and the two decoctions have potential antimicrobial activity against MRSA and further studies should be carried out to determine the cell cytotoxicity and in vivo activity of this extract.

Smartphone Addiction- A Disease in the Stock Market Driving Herding and Overconfidence – A PLS - SEM Analysis

This article examines the smartphone-loved human behavior and the development of psychological biases leading to irrational investment decision-making. We use a survey among a sample of 95 equity investors in the Colombo Stock Exchange and analyze the results using the Partial Least Squares- Structural Equation Modelling approach. We confirm the existence of herd behavior and overconfidence bias which are triggered by smartphone addiction. Investment decisions are strongly influenced by overconfidence while overconfident investors show an ability to mediate the influence of herding. The findings indicate the risk of smartphone and social media addiction, a silent disease driving mispricing in equity markets. &nbsp; Key words: Overconfidence, Herd behavior, Social Media Addiction, Investment Decisio

Determination of Glycaemic Responses of Low Fat Milk Incorporated with Whey Proteins and Oats Powder

International audienc

Evaluation of current condition state of reinforced concrete structures exposed to severe environmental condition

Deterioration of reinforced concrete structures arise due to corrosion of steel present in concrete which leads to structural failure. A number of techniques and methods are being followed and studied by various researchers to predict the service life of the reinforced concrete (RC) structures. Chlorides initiate the corrosion of embedded reinforcements, which not only produces signs of deterioration on the concrete surface, such as rusting, cracking and spalling, but also reduces the load-carrying capacity. This paper discusses service life prediction methods of RC structures exposed to severe environmental conditions. Several methods were used to predict the service life and current condition state of the existing structures. Based on the mathematical modeling, the corrosion process could be formulated by three stages. They are namely, the initiation time (tc), the de-passivation time (tp), and the corrosion propagation time (tcorr). The total service life of RC structures can be expressed as summation of these time periods. In addition, crack observation method based on visual observation on the samples and existing structures and Accelerated Corrosion Testing Method (ASTM) was carried out at the laboratory. To identify the diffusion coefficient of the samples, the Rapid Chloride Penetration Test (RCPT) was carried out at the laboratory. Current condition assessment of the existing concrete structures was evaluated by using nondestructive techniques. This paper briefly discusses the current status of RC structures deteriorated by chloride attack in the Galle area, experimental investigation results and numerical analysis of corrosion cracking

Seismic Analysis of Guyed Mast Towers in Sri Lanka

Abstract: With the rapid development of the telecommunication sector in the country, telecommunication/broadcasting towers play a vital role in telecommunication and broadcasting sectors. There are many structural forms available for towers and guyed mast is one such type commonly seen in country sides of Sri Lanka where land is available for cheaper price. Moreover, in the case of very tall tower is needed, guyed mast is more economical solution than self-supporting towers. The failure of a guyed tower especially under a disaster situation such as earthquake is a major concern in many ways. One is the failure of communication/broadcasting may hamper the communication needs to carry out rescue and other essential operations. Further, failure of a tower may itself cause a considerable economic loss as well as damages to human life. Therefore, checking of structural performance tower under seismic and other extreme weather effects is quite vital. Even though, Sri Lanka was believed to have no seismic threats, presently a strong argument is going on amongst the professionals regarding the seismic condition of our country with the reported earth tremors in recent times. Hence, evaluating the structural performance of existing telecommunication/ broadcasting towers under seismic loads is utmost important since almost all existing towers have not been designed considering seismic forces due to traditional belief that Sri Lanka will not be subjected to earthquakes of appreciable magnitudes. Considering the above situation, assessment of structural performance of exiting Guyed mast towers (which were not initially designed considering earthquake loading) under possible earthquake loading was selected as the objective of this study. Accordingly, behavior of existing Guyed mast towers under seismic loading using ANSI/TIA-222-G tower design code was studied and results, observations and conclusions based on this analysis are presente