New advances in the in-vitro culture of Dientamoeba fragilis

Dientamoeba fragilis is an intestinal protozoan in humans that is commonly associated with diarrhoea and other gastrointestinal complaints. Studies conducted to investigate the biology of this parasite are limited by methods for in vitro cultivation. The objective of this study was to improve a biphasic culture medium, based on the Loeffler's slope, by further supplementation in order to increase the yield of trophozoites in culture. The current in vitro culture of D. fragilis is a xenic culture with a mix of bacteria. Three different liquid overlays were evaluated including Earle's balanced salt solution (EBSS), PBS and Dulbecco's modified PBS (DPBS), for their ability to support the in vitro growth of D. fragilis trophozoites. Out of these 3 overlays EBSS gave the highest increase in the trophozoite numbers. The effect of supplementation was analysed by supplementing EBSS with ascorbic acid, ferric ammonium citrate, L-cysteine, cholesterol and alpha-lipoic acid and quantification of in vitro growth by cell counts. A new liquid overlay is here described based upon EBSS supplemented with cholesterol and ferric ammonium citrate that, in conjunction with the Loeffler's slope, supports the growth of D. fragilis trophozoites in vitro. This modified overlay supported a 2-fold increase in the numbers of trophozoite in culture from all 4 D. fragilis isolates tested, when compared to a PBS overlay. These advances enable the harvest of a larger number of trophozoites needed for further studies on this parasite. © Cambridge University Press 2012

A virtual odometer for a Quadrotor Micro Aerial Vehicle

This paper describes the synthesis and evaluation of a "virtual odometer" for a Quadrotor Micro Aerial Vehicle. Availability of a velocity estimate has the potential to enhance the accuracy of mapping, estimation and control algorithms used with quadrotors, increasing the effectiveness of their applications. As a result of the unique dynamic characteristics of the quadrotor, a dual axis accelerometer mounted parallel to the propeller plane provides measurements that are directly proportional to vehicle velocities in that plane. Exploiting this insight, we encapsulate quadrotor dynamic equations which relate acceleration, attitude and the aerodynamic propeller drag in an extended Kalman filter framework for the purpose of state estimation. The result is a drift free estimation of lateral and longitudinal components of translational velocity and roll and pitch components of attitude of the quadrotor. Real world data sets gathered from two different quadrotor platforms, together with ground truth data from a Vicon system, are used to evaluate the effectiveness of the proposed algorithm and demonstrate that drift free estimates for the velocity and attitude can be obtained

PRESCHOOL TEACHERS’ CONCERNS ON EDUCATIONAL THEORIES AND VIEWS OF EDUCATIONISTS TO DEVELOP CREATIVITY IN THE TEACHING- LEARNING PROCESS

The global attention on research in preschool education has increased and there is an immense motivation in the field of research in Sri Lanka. This research shows that the preschool education is a critical way to introduce and develop all aspects of a child’s development with a focus on creativity. The mixed method design approach was used in this research and a stratified random sample was used to collect data during 2015 and 2016.  Questionnaires, Interviews and observations were used to collect data from the selected preschools in the Colombo district, Sri Lanka.  Descriptive statistics were used for data analysis.The findings showed that the majority of preschools are run by Non- Government organizations, and the State does operate some preschools. Most of the preschool teachers of Government and Non- Government preschools were not aware of creativity as a learning concept. It was observed that teachers use several methods that did not promote creativity. Preschool teachers mostly provided instructions while trying to keep children quiet in order to manage the classroom. The majority of preschool teachers stated that they faced problems in preparing lessons to develop children’s creativity. In conclusion, it showed that preschool teachers do not have adequate training and knowledge regarding the importance of creativity and its implications for the education of children.Findings of this research are expected to be shared with relevant authorities in order to improve teacher training, curriculum development and further research on preschool education

Chikungunya as a cause of acute febrile illness in southern Sri Lanka

10.1371/journal.pone.0082259PLoS ONE812-POLN

Evaluation of salt content and effectiveness of excessive salt reduction methods in selected commercially available dried fish types in Sri Lanka

High salt intake elevates the risk of non-communicable diseases such as high blood pressure, cardiovascular diseases and stroke worldwide. Sri Lanka has recorded in 2010 as the country with highest average fish & fish products consumption in South Asia. In the current study, salt in ten types of commonly available dried fish namely; sprats, prawns, smoothbelly sardinella, queen fish, cat fish, sail fish, shark, skipjack tuna, Bombay duck and trenched sardinella was analyzed and determined salt reduction methods with minimal protein loss. Four salt reduction methods were tested; Method 1: washed with water at Room Temperature (RT) for five times; Method 2: washed with water for five times at RT and kept in hot water for 5min; Method 3: washed with water for five times at RT and boiled for 5min; Method 4: washed with water for five times at RT and kept in coconut water for 5min. Using Volhard method, sodium chloride was analyzed while protein was determined using Kjeldahl method. All four methods showed significant reduction of salt level in tested dried fish (p < 0.05). Among the tested salt reduction methods, Method 3 showed the highest salt reduction for all types of dried fish except smoothbelly sardinella and cat fish.The highest salt mean value of 28.8% was recorded in queen fish and the lowest mean value of 12.8% was recorded in smoothbelly sardinella. The highest protein loss was recorded in Method 3. To reduce considerable amount of salt, the easiest and fairly effective method is method 1 except for prawns and Shark. Although higher salt reduction showed in method 2 and 3, they are not recommended due to high protein loss, high energy expenditure and reduction of freshness of dried fish. Method 4 can be applied for all dried fish types because it is economical and reduces considerable amount of salt, removes less amount of protein comparatively. The results revealed that all tested dried fish except smoothbelly sardinella contain significantly high amount of salt (p < 0.05) than the standard value specified (12%) by the Sri Lanka Standards Institution (SLSI).Keywords: Dried fish, protein loss, salt-intake, salt reduction, non-communicable disease

Accurate Crop Spraying with RTK and Machine Learning on an Autonomous Field Robot

The agriculture sector requires a lot of labor and resources. Hence, farmers are constantly being pressed for technology and automation to be cost-effective. In this context, autonomous robots can play a very important role in carrying out agricultural tasks such as spraying, sowing, inspection, and even harvesting. This paper presents one such autonomous robot that is able to identify plants and spray agro-chemicals precisely. The robot uses machine vision technologies to find plants and RTK-GPS technology to navigate the robot along a predetermined path. The experiments were conducted in a field of potted plants in which successful results have been obtained.Comment: 7 pages, 12 figures, Journa

Lithium chloride selective ion-pair recognition by heteroditopic [2]rotaxanes †

The first heteroditopic [2]rotaxane host systems capable of strong and selective binding of lithium chloride ion-pair species are described. Importantly, a cooperative ‘switch on’ mechanism was found to operate, in which complexation of a lithium metal cation enhances the halide anion affinity of the rotaxanes via a combination of favourable proximal electrostatic and preorganised allosteric effects. The mechanically bonded rotaxane host design features a macrocycle component possessing a 2,6-dialkoxy pyridyl cation binding motif and an isophthalamide anion binding group, as well as an axle component functionalised with either a halogen bonding (XB) iodotriazole or hydrogen bonding (HB) prototriazole moiety. Extensive quantitative 1H NMR titration studies in CD3CN/CDCl3 solvent mixtures determined enhanced ion-pair binding affinities for lithium halides over the corresponding sodium or potassium halide salts, with the axle prototriazole-containing HB rotaxane in particular demonstrating a marked selectivity for lithium chloride. Solid-state X-ray crystallographic studies and computational DFT investigations provide evidence for a [2]rotaxane host axle-separated ion-pair binding mode, in which complementary cation and anion binding motifs from both the macrocycle and axle components act convergently to recognise each of the charged guest species

Leveraging knowledge graphs for analysing human vulnerabilities in phishing attacks.

Phishing attacks remain one of the most effective social engineering threats, exploiting human vulnerabilities rather than technical weaknesses. This study leverages knowledge graphs to analyse and model human susceptibility to phishing attacks by integrating anonymised simulated phishing data with an ontological framework. By mapping user interactions with phishing emails and linking them to psychological traits, we uncover patterns of behaviour that inform cybersecurity training and risk mitigation. Our analysis focuses on response times, reporting behaviours, and susceptibility across different user groups. The results highlight that curiosity-driven phishing emails yield significantly higher engagement than fear-based tactics, demonstrating the cognitive biases that adversaries exploit. Additionally, rapid responses where users engage with phishing emails instantly suggest impulsive, emotion-driven decision making, while delayed but still erroneous interactions indicate susceptibility to more sophisticated deception techniques

Propofol and Kearns-Sayre Syndrome: An idiographic approach

With the focus on an idiographic approach whereby the observations incorporated the various dimensions of individual functioning ‘top-down’ to ‘bottom-up’, this case report describes the successful management of a 14-year-old girl with Kearns-Sayre syndrome and Dyggve-Melchior-Clausen disease requiring a transvenous permanent pacemaker implantation for complete heart block. The patient presented to a tertiary care centre in Muscat, Oman, in 2023 seeking consultation. The current idiographic approach appears to have a heuristic value for 2 interrelated reasons. Firstly, it is unlikely that even tertiary care units can accrue such rare presentations and scrutinise them under nomothetic approach. Secondly, by employing the idiographic approach that is capable of examining each case in-depth, the aspiration for good health and well-being may come to the forefront. To the best of the authors’ knowledge this is the first published idiographic report in anaesthesia care. Keywords: Intravenous Anaesthetics; Artificial Pacemaker; Kearns-Sayre Syndrome; Propofol; Idiographic Approach; Case Report; Oman