Characterization Of Bacteriophages From Environmental Water Samples And The Potential Of Bacteriophages Tailspike Proteins (tsp) In Bacteria Detection

ABSTRACT CHARACTERIZATION OF BACTERIOPHAGES FROM ENVIRONMENTAL WATER SAMPLES AND THE POTENTIAL OF BACTERIOPHAGES TAILSPIKE PROTEINS (TSP) IN BACTERIA DETECTION by GAYATHRI UPEKSHA GUNATHILAKA May 2014 Advisor: Dr. Yifan Zhang Major: Nutrition and Food Science Degree: Master of Science The high abundance of phage in the environment and their specificity with the bacteria host make them an excellent tool for bacteria detection. To characterize phage specific to Salmonella and E. coli from water samples in the Southeastern Michigan and to develop a novel bacterial detection method using phage, environmental water samples were collected from rivers and waste water treatment plant (WWTP) in Southeastern Michigan. E. coli and Salmonella phage were isolated from water samples using soft agar overlay technique with multiple indicator strains. Host range of phage was determined using 18 Salmonella strains and 14 E. coli strains. Transmission Electron Microscopy (TEM) was used to visualize the morphology of representative phage. Tailspike Protein (TSP) purified from E. coli O157 phage ФV10 was functionalized on a graphene field-effect-transister (FET). The specificity of TSP and E. coli O157 binding was measured by the shift of Dirac Point. A total of 70 Salmonella phage and 33 E. coli phage were purified. Twelve E. coli phages were able to grow in all 4 E. coli O157 strains tested. Out of 37 host range patterns in Salmonella phage, all the patterns were able to multiply in 3 strains and above. Out of 9 host range patterns observed in E. coli phage, 6 were able to multiply in 3 strains and above. This suggests a broad host range of the phage recovered. According to the TEM pictures, all of the E. coli phages and some of Salmonella phages were tailed phages. Detectable conductance change was observed when E. coli O157 binds to TSP-functionalized graphene FET whereas very small shift in Dirac Point was caused by Salmonella binding, indicating high specificity of E. coli O157 interaction with TSP. In conclusion, phage with broad host ranges is prevalent in water. Phage has the potential to be applied to bacteria detection

A COMPARATIVE STUDY OF THE CHOICE OF SELF-EMPLOYMENT BETWEEN MEN AND WOMEN IN SRI LANKA

Different characteristics and different roles of both men and women affect the existing gender disparities in self-employment choice in Sri Lanka. This study mainly focuses on comparing the determinants of self-employment choice between men and women in Sri Lanka. The Sri Lanka Labour Force Survey conducted by the Department of Census and Statistics in 2018 was used as the main data source. Three binary logistic regression models were applied for analyzing. Based on the results, it was revealed that being a female has a significant and negative impact on self-employment choice in Sri Lanka. Sri Lankan Moors and the disabled have a higher tendency while tertiary educated people have a lower tendency towards self-employment for both men and women. Other demographic and health factors including ethnicity, age, marital status, disability, household size, socio-economic factors including level of education, vocational training, family income, digital literacy, geographical factors including residential sector and residential province also affect the self-employment choice for men and women. Finally, gender specific policies were suggested to promote self-employment in Sri Lanka by enhancing awareness, developing infrastructure facilities,introducing educational reforms and conducting training programmes at regional level.Keywords: Choice of Self-employment, Gender Differences, Determinants of Self-employment, Self-employment Policie

Investor sentiment, human capital and Fama French factors: measurement and performance in the Malaysian market

This paper examines pricing implications of investors’ behavioral biasness in the Malaysian equity market. By using monthly data from January 2000, through January 2014, we explore the impact of investor sentiment, human capital, and Fama-French risk factors in multiple factor asset pricing models. A unique seven-variable composite index is used for the measurement of investor sentiment. Results indicate that sentiment is a priced risk, and display the ability to capture returns unexplained by SMB (Small minus Big) and HML (High minus Low) factors. Evidence suggests that sentiment is a source of systemic risk, and effectively explains returns of stocks with opaque characteristics. Modeling aggregate labor income produces insignificant results, suggesting that there are no returns for human capital in the Malaysian equity market. The Fama and French three factor model together with investor sentiment risk achieves a substantial pricing efficiency

A game-based approach towards human augmented image annotation.

PhDImage annotation is a difficult task to achieve in an automated way. In this thesis, a human-augmented approach to tackle this problem is discussed and suitable strategies are derived to solve it. The proposed technique is inspired by human-based computation in what is called “human-augmented” processing to overcome limitations of fully automated technology for closing the semantic gap. The approach aims to exploit what millions of individual gamers are keen to do, i.e. enjoy computer games, while annotating media. In this thesis, the image annotation problem is tackled by a game based framework. This approach combines image processing and a game theoretic model to gather media annotations. Although the proposed model behaves similar to a single player game model, the underlying approach has been designed based on a two-player model which exploits the player’s contribution to the game and previously recorded players to improve annotations accuracy. In addition, the proposed framework is designed to predict the player’s intention through Markovian and Sequential Sampling inferences in order to detect cheating and improve annotation performances. Finally, the proposed techniques are comprehensively evaluated with three different image datasets and selected representative results are reported