Virulence factors of verotoxin-producing Escherichia coli O157:H7

Escherichia coli 0157:H7 is one of several E.coli serotypes that produce Verocytotoxins (VTs); they are collectively called "Verocytotoxin-producing E.coli" (VTEC). VTEC are medically important bacteria which have been implicated in cases of haemorrhagic colitis and haemolytic uremic syndrome. Two distinct VTs are known, VT1 and VT2, and variants of VT2 have been described. They are potent exotoxins which kill mammalian cells by inhibiting protein synthesis. The virulence properties manifested by these organisms include the elaboration of VT1 or VT2 (or both), and the adherence to intestinal epithelial cells via an attaching-effacing mechanism. Many strains carry a 60 MDa plasmid which is thought to be involved in adhesion. Initial data demonstrated that the VTEC 0157.H7 isolates under study possess two virulence factors, production of VTs and adherence to epithelial cells. However, effort has focused on investigating bacterial adherence, largely because attachment of VTEC is thought to be an important pathogenic mechanism since it allows colonisation, which facilitates toxin delivery, and adherence may be sufficient to cause diarrhoea in experimental animals in the absence of VTs. Moreover, a better understanding of the adhesion mechanism should help in finding ways by which adherence can be prevented. Since the bacterial-mucosal interactions are complicated in vivo by events and conditions that are not reproduced in current in vitro tests, a series of experiments were designed to investigate bacterial adherence to epithelial cells under conditions which are as close as possible to the in vivo situation. Significantly different data were obtained when quantitative adherence assays were performed under different physiological conditions, (different growth media, growth phase, pH values, low iron and oxygen limitation). Both iron-restricted, and oxygen- limited media induced a reduction in the final cell density, however, anaerobiosis significantly increased the adherence capacity of VTEC 0157:H7 to HeLa cells while low iron caused a reduction in the number of adherent bacteria. Actively growing cells in the exponential phase were more adherent to HeLa cells than cells in the stationary phase. Since adhesion results from mutual recognition of surface structures from both the bacterial cell (adhesin) and the host cell (receptor), the bacterial cell envelope, and the HeLa cell outer membranes were investigated. Results of the preliminary characterisation of VTEC 0157:H7 surface components which have been implicated as adherence factors indicated that these strains are not fimbriated, however, they have been shown to be capable of binding to epithelial cells. Further studies were therefore, focused upon the identification of nonfimbrial adhesin(s). The use of competitive inhibitors, such as bacterial outer membrane extracts (OMPs), isolated lipopolysaccharides (LPS) and rabbit antisera to the H-7 flagella, OMPs, and LPS suggested that the role of H-7 flagella is insignificant, the LPS may in part be involved, but the OMPs seemed to have the major role in mediating attachment of 0157:H7 to HeLa cells. The expression of OMPs under variable cultural conditions was examined, and significant differences were detected by the SDS-PAGE analysis of these extracts. The expression and repression of certain proteins was apparent under anaerobiosis, iron-restriction, different pH values and different bacterial growth phases. HeLa cell outer membranes were studied to identify the receptors on the host cell. Purified outer membranes were analysed by SDS-PAGE and used as inhibitors of bacterial adherence. Two proteins were identified by immunoblotting as a potential receptors

Thesis on Entrepreneurship Perceptions and Inclinations among Students : A Comparative Study Across Multiple Disciplines

This study explores the internal and external views of entrepreneurship among students from various fields of study, including medicine, law, business, engineering and humanities. It investigates the likelihood of students engaging in entrepreneurial activities within their respective fields and identifies target groups with less positive perceptions and lower inclinations towards entrepreneurship. Through a combination of qualitative and quantitative research methods, including a literature review and an interview with an entrepreneur from the medical field, we found that students in medicine show the least interest in entrepreneurship, while students in business show the highest, with other fields of study falling in between. These insights highlight the need for comprehensive entrepreneurship education and courses tailored to the specific fields of study to foster an entrepreneurial mindset among students by exposing them to its possibilities. By promoting innovation and entrepreneurial thinking, such initiatives hold significant potential for creating valuable opportunities within different academic domains.

Thesis on Entrepreneurship Perceptions and Inclinations among Students : A Comparative Study Across Multiple Disciplines

This study explores the internal and external views of entrepreneurship among students from various fields of study, including medicine, law, business, engineering and humanities. It investigates the likelihood of students engaging in entrepreneurial activities within their respective fields and identifies target groups with less positive perceptions and lower inclinations towards entrepreneurship. Through a combination of qualitative and quantitative research methods, including a literature review and an interview with an entrepreneur from the medical field, we found that students in medicine show the least interest in entrepreneurship, while students in business show the highest, with other fields of study falling in between. These insights highlight the need for comprehensive entrepreneurship education and courses tailored to the specific fields of study to foster an entrepreneurial mindset among students by exposing them to its possibilities. By promoting innovation and entrepreneurial thinking, such initiatives hold significant potential for creating valuable opportunities within different academic domains.

Procès-verbal n° 286

Pauty Edmond, 'Urabi 'Aly Zaki el-. Procès-verbal n° 286. In: Comité de Conservation des Monuments de l'Art Arabe. Fascicule 38, exercice 1936-1940, 1944. pp. 46-49

Nach dem Sturm : (after the storm) : a prediction of the downfall of the British Empire /

Also available online at: http://nla.gov.au/nla.aus-vn1955401; FERG copy from Ferguson First World War, 1914-1919 pamphlet collection.After the stor

Procès-verbal n° 286

Pauty Edmond, 'Urabi 'Aly Zaki el-. Procès-verbal n° 286. In: Comité de Conservation des Monuments de l'Art Arabe. Fascicule 38, exercice 1936-1940, 1944. pp. 46-49

Harnessing IoT, E-Business, and Digital Marketing for Enhancing User Satisfaction and Performance in UAE\u27s Hotel Industry: An Empirical Study

The hotel industry in UAE is one of the major source of revenue, competition among the hotels is mounting every day. Therefore, the top management of these hotels needs to identify the factors to improve their performance. This study aims to analyze the effect of IoT, E-business strategy, digital marketing and performance through user satisfaction. The quantitative research was conducted by distributing questionnaires among the customers of different hotels of UAE. The sampling technique adopted in this study was purposive sampling. The usable questionnaires used for analysis were 212. The study adopted the SEM technique and PLS tool for analysis. The results indicate that digital marketing, IoT, and e-business strategy significantly impact the user satisfaction. User\u27s satisfaction is an important predictor of the performance of hotels. These findings can be valuable for decision-makers in the UAE hotel industry

The Role of Social Media Usage, E-WOM, and Perceived Enjoyment in Shaping Customer Attitudes and Blockchain Adoption Loyalty in UAE Banking: A Quantitative Investigation

Technology is shaping the banking sector around the globe. Therefore, the prime objective of this research was to examine the relationship among social media use, e-WoM, perceived enjoyment and customer\u27s attitude towards loyalty to the use of Blockchain technology in the context of U.A.E. banks. This study used a cross-sectional research design and quantitative methods for data collection. Five-point Likert scale was used to develop the well-designed questionnaire for data collection. A simple random sampling technique was adopted to distribute the questionnaire among respondents. A sample of one hundred seventy-four observations was analyzed using Smart PLS 3.3.9. The findings confirmed the significant and direct effect of social media use, e-WoM, and perceived enjoyment on customers\u27 attitudes. The direct effect of customer attitude on Blockchain adoption was also supported. The findings also revealed the important mediating role of customer attitude as well. The findings are helpful for policymakers and academicians