A preliminary study on Naegleria species in water bodies of Kurunegala district, Sri Lanka

Introduction and Objective: Species belonging to the genus Naegleria are free-living ubiquitous protozoa. They have been isolated from most regions of the world. N. fowleri causes an acute, fulminant and rapidly fatal infection involving the central nervous system (CNS) in humans. It is known as primary amoebic meningoencephalitis (PAM). Infection is generally acquired while swimming, diving and total submersion for bathing in freshwater-lakes and ponds. Many inland fresh water bodies are present in Sri Lanka. These water bodies are frequently used by people for their daily needs. However, studies have not yet been conducted to determine the prevalence of Naegleria species occurring in local water bodies. The present study was therefore, carried out to isolate Naegleria species from selected water bodies located in four Divisional Secretariat (DS) divisions in the Kurunegala district, Sri Lanka.Methods: Two different sites (clear and turbid water) of each tank were selected for sampling. Two water samples (surface water and deep water) were collected from each site (4 samples from one tank). Altogether, eighty water samples were collected from 20 tanks. Culture, enflagellation test and staining were done to detect Naegleria species. ArcGIS 10.3 and MINITAB (14) software were used for the data analysis.Results: Flagella transformation was observed in 19 (47.5%) surface water samples and 11 (27.5%) deep water samples. Of 20 tanks, 10 were positive for Naegleria species.Conclusions: Findings of the present study suggest that more specific genotyping studies are needed to confirm the presence of pathogenic N. fowleri in the study area.</p

Beyond Grief: An Anthropological Exploration of Resilience, Identity, and Social Dynamics among Widows

The ritualistic behaviors associated with death encompass actions that signify the significant impact of the loss on both the bereaved individual and the community. When an individual loses a spouse through death, the absence of the deceased has been resulted in the loss of both social interactions and emotional support. This often intensifies the necessity for the development of alternative social relationships. Therefore, the research problem at hand delves to unravel the multifaceted elements of widowhood, focusing on how widows in various socioeconomic circumstances develop and deploy resilient strategies to cope with grief. The general objective of this research is to illuminate the mechanisms through which widows reconstruct their identities amid the complex interplay of societal expectations and personal aspirations. This study is based on purposively selected twenty widow households of Ratmalana DS division, Colombo district, Sri Lanka. The qualitative methods and techniques have been applied to collect data including interviews, case studies, focus group discussions and observation methods. The findings of the research reveal insights into their resilience mechanisms, influenced by cultural and societal factors. Widows face societal stigma and gender-based stereotypes, leading to limited participation in social events. The economic impact on widows is shaped by historical practices like Sinhalese land tenure and discriminatory inheritance laws. Financial challenges arise from shifting family structures and gender disparities in employment. The study highlights varied income sources, with self-employment common post-spousal loss. Financial aid to widows is limited, and government initiatives fluctuate in utility. Support networks play a crucial role in widows' financial stability, offering multifaceted assistance. The research findings suggest that widows encounter distinct difficulties within their gender roles. As the sole caregiver, they strive to maintain their family's socio-cultural and economic stability as household leaders, simultaneously managing household affairs and finances. Widows, identified as individuals who grapple with both financial and emotional support in modern society, face significant challenges in meeting these responsibilities

ANALYSIS OF ISSUES AND CONSTRAINTS ASSOCIATED WITH PLASTIC RECYCLING INDUSTRY IN SRI LANKA

High consumption of plastics inevitably leads to the production of large amounts of plastic waste especially because a substantial part of produced plastics is used for packaging. Therefore, suppression of environmental pollution by plastic waste is a task of significant importance. Main objectives of the study are to assess the current status of plastic recycling industry in Sri Lanka and identification of issues related to plastic recycling industry. A questionnaire survey was carried out to collect data from all plastic waste collectors and recyclers registered in the CEA. Field observations were taken by studying twenty randomly selected plastic recycling industries in the Western Province.The highest percentage (93%) of recyclers use PP (Polypropylene) as a raw material in plastic recycling industry in Sri Lanka compared to other polymers. Waste collection by waste pickers from dumps and streets are the main source of plastic waste collection for recycling. About 95% of plastic and polythene waste obtained for recycling are in unsorted  condition and 91% are in unclean condition. Private wells are the most widely used (72%) source of water for washing of waste plastic. None of the plastic and polythene waste recycling industries in Sri Lanka has a wastewater treatment facility. Therefore  78% of plastic and polythene waste collectors and recyclers discharge their industrial wastewater in to the nearest water body.Field observations indicate that most of the plastic waste recycling industries are running under capacity due to insufficient collection of plastic materials. In addition, lack of standard techniques for waste plastic sorting, problems of getting EPL and not having suitable lands for the establishment of large scale waste plastic recycling plants are the major issues currently faced by the plastic waste recycling industries in the Western Province

Use of Photocatalysis for Degradation of Glyphosate in Potable Water of CKDu Prevalent Areas

Glyphosate, which is commercially available as Roundup®, was the most widely used herbicide in Sri Lanka until recently. Recent studies report the presence of glyphosate in different water sources (drinking water, surface water, groundwater) in the Chronic Kidney Disease of unknown etiology (CKDu) prevalent areas containing elevated hardness levels. Additionally, WHO studies conducted in 2013, provide evidence of the presence of glyphosate in trace levels in urine samples of CKDu subjects. Thus, glyphosate is suspected to be one of the causal factors for CKDu and its removal, when present in potable water with high hardness levels, is a challenging engineering task. Photocatalysis is recognised to be one of the promising technologies for degradation of glyphosate. Hence, this study focuses on investigating the effectiveness and efficiency of the photocatalysis process for degradation of glyphosate from potable waters containing high hardness levels. Experiments were conducted with high purity Glyphosate and Roundup® in the absence (0 mg/l as CaCO3) and presence of hardness (1,500 mg/l as CaCO3). A sunlight activated water purifier bag available in the market that consists of a Titanium Dioxide membrane was used for application of the photocatalysis process. A 3.0 L water sample containing Glyphosate/Roundup® (glyphosate concentration 1 mg/L) was continuously exposed to sunlight for six (06) hours. A solar irradiance meter was used to measure the sunlight intensity. Samples from the reaction solution were collected at predetermined time intervals and analysed for glyphosate and amninomethyphosphonic acid (AMPA) using GC/MS and LC/MS in the absence and presence of hardness, respectively. A rapid decrease in glyphosate concentration to levels below 0.7 mg/l (USEPA Maximum Contaminant Level) was observed during the first 60 minutes of reaction time under all experimental conditions studied. The concentration of AMPA detected was below the level of quantification in all experiments implying that complete degradation of Glyphosate has occurred until inorganic phosphate is produced. When using high purity glyphosate or Roundup®, slower degradation rates were observed in the presence of hardness compared to that in the absence of hardness. Retardation of glyphosate degradation in the presence of hardness could be attributed to the enhanced persistence of glyphosate due to the formation of glyphosate-Ca and -Mg complexes when hardness is present in water. Similarly, slower degradation rates were observed with Roundup® compared to that of with high purity glyphosate, both in the absence and presence of hardness. The presence of the major adjuvant surfactant [polyethoxylatedtallowamine, (POEA)], which is introduced as an inert ingredient during Roundup® production seems to have enhanced the persistence of glyphosate in water thus causing retardation of Glyphosate degradation by the photocatalysis process. In conclusion, photocatalysis is an effective and efficient technique that could be used to degrade glyphosate in potable water of CKDu prevalent areas in spite of the possible antagonistic effects observed on Glyphosate degradation due to the presence of hardness and/or surfactants.Keywords: CKDu, Glyphosate, Photocatalysi

Finite element study of the stress field near pressurized and non-pressurized flaws in rock specimens subject to uniaxial and biaxial loads

The finite element code ABAQUS is used to model a typical granite specimen subjected to either uniaxial or biaxial compression, with two pre-fabricated flaws with the geometry 2a-30-30 in which only one flaw is pressurized. The maximum and minimum principal stresses as well as the maximum shear stresses are analyzed around the flaw tips and along the bridge between the inner flaw tips of the pressurized and non-pressurized flaws. When the specimen is loaded uniaxially, the maximum principal stresses in the bridge between inner flaw tips are tensile near the pressurized flaw and decrease significantly as one moves towards the non-pressurized flaw. For the biaxial loading, mainly compressive principal stresses are observed for low hydraulic pressures; tensile stresses start to develop for larger hydraulic pressures, but only near the pressurized flaw. For both uniaxial and biaxial cases, tensile and shear cracks may occur near the pressurized flaw but are not theoretically possible near the non-pressurized flaw

Growth characteristics and meat quality atributes of Clam (Geloina vexans) and Oysters (Crassostrea madrasensis) harvested from two lagoons of Sri Lanka.

772-777The present study was focused to evaluate nutritional quality parameters, Ecophysiological and commercial quality indicators of clam (Geloina vexans) and oyster (Crassostrea madrasensis) at two growth stages (4 months and 6 months) in two different Sri Lankan sites, namely Bolgoda lagoon in Moratuwa area and Pitipana lagoon in Negombo area. According to the results of this study total saturated fatty acids (34.4%) as well as total mono saturated fatty acids are high in clams of Bolgoda lagoon. However, total polyunsaturated fatty acids are high in clams of Negambo lagoon. Results revealed that crude protein level is significantly (p<0.05) higher in both species grown in Bolgoda lagoon (CP% 70.8±1.42g/100g and 48.97±2.38g/100g clams in Bolgoda and Negombo respectively while CP% 34.12+1.18 and 45.2+2.23g/100g oysters in Bolgoda and Negambo respectively). However intervalval fluid contents of 6 months age clams and oysters in Negombo are significantly higher than Bolgoda oysters (P<0.05) which are 11.39±1.68 g/100g and 9.11± 1.68 g/100g respectively. Water salinity, temperature and pH are some values which are significantly higher in Negombo lagoon than Bolgoda (P<0.05) while dissolved oxygen and resistivity are significantly higher in Bolgoda than Negombo. Results revealed that availability of planktons is high in Bolgoda lagoon. And this may be the possible reason for high CP, ash, DM and meat content in clams and oysters of Bolgoda lagoon. Rich lagoon conditions in Bolgoda lagoon has caused to the high nutritional value and high demand of bivalves in Bolgoda lagoon in Sri Lanka

A systematic literature review and meta-analysis on cross project defect prediction

Abstract Background: Cross project defect prediction (CPDP) recently gained considerable attention, yet there are no systematic efforts to analyse existing empirical evidence. Objective: To synthesise literature to understand the state-of-the-art in CPDP with respect to metrics, models, data approaches, datasets and associated performances. Further, we aim to assess the performance of CPDP versus within project DP models. Method: We conducted a systematic literature review. Results from primary studies are synthesised (thematic, meta-analysis) to answer research questions. Results: We identified 30 primary studies passing quality assessment. Performance measures, except precision, vary with the choice of metrics. Recall, precision, f-measure, and AUC are the most common measures. Models based on Nearest-Neighbour and Decision Tree tend to perform well in CPDP, whereas the popular naïve Bayes yields average performance. Performance of ensembles varies greatly across f-measure and AUC. Data approaches address CPDP challenges using row/column processing, which improve CPDP in terms of recall at the cost of precision. This is observed in multiple occasions including the meta-analysis of CPDP versus WPDP. NASA and Jureczko datasets seem to favour CPDP over WPDP more frequently. Conclusion: CPDP is still a challenge and requires more research before trustworthy applications can take place. We provide guidelines for further research