The effect of thermophoresis on the discharge parameters in complex plasma experiments

Thermophoresis is a tool often applied in complex plasma experiments. One of the usual stated benefits over other experimental tools is that changes induced by thermophoresis neither directly depend on, nor directly influence, the plasma parameters. From electronic data, plasma emission profiles in the sheath, and Langmuir probe data in the plasma bulk, we conclude that this assumption does not hold. An important effect on the levitation of dust particles in argon plasma is observed as well. The reason behind the changes in plasma parameters seems to be the change in neutral atom density accompanying the increased gas temperature while running at constant pressure.Comment: 14 pages, 12 figure

Evaluation of the undergraduate family medicine programme of Faculty of Medicine, University of Kelaniya : quantitative and qualitative student feedback

Background: Worldwide there is an increasing emphasis on the importance of primary care. The ministry of health Sri Lanka issued a directive in 2016 that training of doctors in primary care should be strengthened. Medical students of the Faculty of Medicine, University of Kelaniya follow a 1 month long clinical appointment in family medicine in their fourth year of study. Methods: Feedback is taken from students on completion of the appointment. Half the students from each group complete a pre tested structured feedback questionnaire that consists of answers to questions based on a likert scale with a space for free comments. The other half provide qualitative feedback. In this evaluation data were gathered from 185 (98%) students from all eight clinical groups throughout the year 2016. Quantitative data were analysed using SPSS version 22. Inductive thematic analysis was used to analyse the qualitative data from the Round Robin activity and free comments from the questionnaire. Results: The qualitative feedback provided a richer indepth overview of student ideas on the appointment compared to the quantitative data. In reflection of a desire for learning to be of relevance students wanted clinically oriented teaching focused on management. They preferred active teaching learning methods such as the opportunity to conduct consultations and receive immediate feedback. Students had a high regard for the teaching sessions by general practitioners at their clinics. The appointment had created an interest in the discipline of family medicine which could have an impact on future choice of career. There were indications to suggest that student attitudes towards patients may have evolved to be more patient centred. Students appreciated the inclusive and low stress ambience of the learning environment. Conclusions and recommendations: Regular evaluation of teaching programmes helps maintain accountability of faculty and paves the way for more student centred teaching through the incorporation of students’ views in devising teaching methods. This evaluation found that qualitative feedback provided more descriptive material to reflect on and therefore improve teaching on the programme. It is recommended that more use should be made of qualitative methodologies in programme evaluations

Dynamic Limits on Planar Libration-Orbit Coupling Around an Oblate Primary

This paper explores the dynamic properties of the planar system of an ellipsoidal satellite in an equatorial orbit about an oblate primary. In particular, we investigate the conditions for which the satellite is bound in librational motion or when the satellite will circulate with respect to the primary. We find the existence of stable equilibrium points about which the satellite can librate, and explore both the linearized and non-linear dynamics around these points. Absolute bounds are placed on the phase space of the libration-orbit coupling through the use of zero-velocity curves that exist in the system. These zero-velocity curves are used to derive a sufficient condition for when the satellite's libration is bound to less than 90 degrees. When this condition is not satisfied so that circulation of the satellite is possible, the initial conditions at zero libration angle are determined which lead to circulation of the satellite. Exact analytical conditions for circulation and the maximum libration angle are derived for the case of a small satellite in orbits of any eccentricity.Comment: Submitted to Celestial Mechanics and Dynamical Astronom

Malaria Diagnosis and Hospitalization Trends, Brazil

Malaria Diagnosis and Hospitalization Trends, Brazi

Novel testing and characterization of GFRP bars in compression

Glass fibre reinforced polymer (GFRP) bars have now been increasingly used as longitudinal reinforcement in concrete columns. In column design and analysis, the contribution of GFRP bars to compression is often ignored or is estimated as a fraction of its tensile strength due to the limited understanding on their compressive behaviour. Moreover, there exists no standard test method to characterise the properties of GFRP bars in compression. This study implemented a novel test method to determine and characterise the compressive properties of high modulus GFRP bars. During the preparation of test specimens, hollow steel caps filled with cementitious grout were used to confine the top and bottom ends of the GFRP bars. The effects of the bar diameter (9.5, 15.9, and 19.1 mm) and the unbraced length-to-bar diameter ratio, Lu/db (2, 4, 8, and 16) were investigated on the compressive strength of the bars. The results showed that the increase in bar diameter increases the micro-fibre buckling and decreases the compressive-to-tensile strength ratio. Similarly, the failure mode changed from crushing to fibre buckling with the increase of Lu/db ratio. Simplified theoretical equations were proposed to reliably describe the compressive behaviour of GFRP bars with different bar diameters and Lu/db ratios

THE ROLE OF ENVIRONMENTALISTS ON THE SUSTAINABLE USE OF MEDICINAL PLANTS, FROM AN AYURVEDIC PRACTITIONER'S POINT OF VIEW

The unique biological diversity of Sri Lanka is vital for the long term welfare of her ownpeople. But her natural forest cover which harbours a rich species diversity is dwindlingrapidly due to various reasons. It is customary for the traditional Ayurvcdic physicians ofSri Lanka to use plants as the major original source of drugs used in the treatment ofdiseases. However, there has been drastic decline in the availability of medicinal plants inSri Lanka since recent past. Therefore, this issue should be dealt with a multidisciplinaryapproach.A model survey was conducted in the Moneragala district in order to assess the hardshipsfaced hy the traditional physicians due to the scarcity of required varieties of plantingredients. Another survey was conducted among traditional physicians among riverandomly selected districts and also in ayurvedic pharmacies with the objective ofevaluating the status of demand of medicinal plants used for specific diseases usingdiabetes as a model. All these surveys were carried out using structured questionnaires.The outcome of these surveys strongly recommend that there is a great necessity tointegrate reforestation programmes with medicinal plant cultivation in order to cater to thedemand. Therefore. Sri Lanka needs a comprehensive strategy for the development of itsmedicinal plants. In our opinion. it is the responsibility of the environmentalists to adviseand guide the authorities concerned in preserving the medicinal plants which is ourNational heritage as well

Geographic Coincidence of Increased Malaria Transmission Hazard and Vulnerability Occurring at the Periphery of two Tanzanian Villages.

The goal of malaria elimination necessitates an improved understanding of any fine-scale geographic variations in transmission risk so that complementary vector control tools can be integrated into current vector control programmes as supplementary measures that are spatially targeted to maximize impact upon residual transmission. This study examines the distribution of host-seeking malaria vectors at households within two villages in rural Tanzania. Host-seeking mosquitoes were sampled from 72 randomly selected households in two villages on a monthly basis throughout 2008 using CDC light-traps placed beside occupied nets. Spatial autocorrelation in the dataset was examined using the Moran's I statistic and the location of any clusters was identified using the Getis-Ord Gi* statistic. Statistical associations between the household characteristics and clusters of mosquitoes were assessed using a generalized linear model for each species. For both Anopheles gambiae sensu lato and Anopheles funestus, the density of host-seeking females was spatially autocorrelated, or clustered. For both species, houses with low densities were clustered in the semi-urban village centre while houses with high densities were clustered in the periphery of the villages. Clusters of houses with low or high densities of An. gambiae s.l. were influenced by the number of residents in nearby houses. The occurrence of high-density clusters of An. gambiae s.l. was associated with lower elevations while An. funestus was also associated with higher elevations. Distance from the village centre was also positively correlated with the number of household occupants and having houses constructed with open eaves. The results of the current study highlight that complementary vector control tools could be most effectively targeted to the periphery of villages where the households potentially have a higher hazard (mosquito densities) and vulnerability (open eaves and larger households) to malaria infection

Low utilization of health care services following screening for hypertension in Dar es Salaam (Tanzania): a prospective population-based study

Drug therapy in high-risk individuals has been advocated as an important strategy to reduce cardiovascular disease in low income countries. We determined, in a low-income urban population, the proportion of persons who utilized health services after having been diagnosed as hypertensive and advised to seek health care for further hypertension management. A population-based survey of 9254 persons aged 25-64 years was conducted in Dar es Salaam. Among the 540 persons with high blood pressure (defined here as BP >or= 160/95 mmHg) at the initial contact, 253 (47%) had high BP on a 4th visit 45 days later. Among them, 208 were untreated and advised to attend health care in a health center of their choice for further management of their hypertension. One year later, 161 were seen again and asked about their use of health services during the interval. Among the 161 hypertensive persons advised to seek health care, 34% reported to have attended a formal health care provider during the 12-month interval (63% public facility; 30% private; 7% both). Antihypertensive treatment was taken by 34% at some point of time (suggesting poor uptake of health services) and 3% at the end of the 12-month follow-up (suggesting poor long-term compliance). Health services utilization tended to be associated with older age, previous history of high BP, being overweight and non-smoking, but not with education or wealth. Lack of symptoms and cost of treatment were the reasons reported most often for not attending health care. Low utilization of health services after hypertension screening suggests a small impact of a patient-centered screen-and-treat strategy in this low-income population. These findings emphasize the need to identify and address barriers to health care utilization for non-communicable diseases in this setting and, indirectly, the importance of public health measures for primary prevention of these diseases

Country development and manuscript selection bias: a review of published studies

BACKGROUND: Manuscript selection bias is the selective publication of manuscripts based on study characteristics other than quality indicators. One reason may be a perceived editorial bias against the researches from less-developed world. We aimed to compare the methodological quality and statistical appeal of trials from countries with different development status and to determine their association with the journal impact factors and language of publication. METHODS: Selection criteria: Based on the World Bank income criteria countries were divided into four groups. All records of clinical trials conducted in each income group during 1993 and 2003 were included if they contained abstract and study sample size. Data sources: Cochrane Controlled Trials Register was searched and 50 articles selected from each income group using a systematic random sampling method in years 1993 and 2003 separately. Data extraction: Data were extracted by two reviewers on the language of publication, use of randomization, blinding, intention to treat analysis, study sample size and statistical significance. Disagreement was dealt with by consensus. Journal impact factors were obtained from the institute for scientific information. RESULTS: Four hundred records were explored. Country income had an inverse linear association with the presence of randomization (chi2 for trend = 5.6, p = 0.02) and a direct association with the use of blinding (chi2 for trend = 6.9, p = 0.008); although in low income countries the probability of blinding was increased from 36% in 1993 to 46% in 2003. In 1993 the results of 68% of high income trials and 64.7% of other groups were statistically significant; but in 2003 they were 66% and 82% respectively. Study sample size and income were the only significant predictors of journal impact factor. CONCLUSION: The impact of country development on manuscript selection bias is considerable and may be increasing over time. It seems that one reason may be more stringent implementation of the guidelines for improving the reporting quality of trials on developing world researchers. Another reason may be the presumptions of the researchers from developing world about the editorial bias against their nationality