Exploiting the Anaerobic Expression of Pyruvate Dehydrogenase for the Production of Biofuels

The Pyruvate dehydrogense complex (PDH) is a primarily aerobic enzyme which catalyses pyruvate to acetyl-CoA and carbon dioxide. Its counterpart in anaerobic metabolism is pyruvate formate lyase (Pfl) which converts pyruvate to acetyl-CoA and formate. A novel fermentation pathway involving PDH rather than Pfl (or equivalent), which retains the reducing equivalents from pyruvate oxidation, could provide a novel route for ethanol production, as well as changes in redox balance opening up opportunities for the production of higher alcohols such as butanol. Utilising PDH for the production of biofuels has been investigated in three microorganisms: Geobacillus thermodenitrificans, Bacillus subtilis, and E. coli. Geobacillus thermodenitrificans does express Pfl, thus PDH is always active in the G. thermodenitrificans regardless of whether the bacterium is growing in aerobic or anaerobic conditions. To utilise this PDH in the production of ethanol a bi-functional alcohol dehydrogenase (AdhE) was introduced to G. thermodenitrificans K1041. Further optimisation of ethanol production was achieved by knocking-out lactate dehydrogenase (Ldh), which would otherwise compete with ethanol for flux from acetyl-CoA, and activity of the PDH promoter verses potential alternative promoters to increase the expression of the native PDH was investigated. Like G. thermodenitrificans, Bacillus subtilis also does not have a PFL pathway, but does have a native Adh so can undergo fermentation, albeit poorly. To increase ethanol production competing fermentation pathways were knocked-out, however this resulted in strains which were unable to grow anaerobically. The activity of the native PDH promoter was investigated, and PDH subsequently upregulated. The production of 1-butanol from B. subtilis was also achieved using expression of Clostridial genes encoding a butanol synthetic pathway from a plasmid and from chromosomal integrations. PDH in Gram-negative bacteria such as E. coli are not active during anerobic growth due to fermentation resulting in elevated levels of intracellular NADH; which in turn triggers negative feedback inhibition of PDH. A consequence of this is E. coli strains which are engineered to produce increased titres of ethanol by knocking-out pfl are unable to grow anaerobically. To alleviate this problem a PDH from gram-positive bacteria was expressed in E. coli. The effect of these PDH was also used to assess their potential benefits on 1-butanol in E. coli, by introducing Clostridial genes encoding a butanol synthetic pathway via plasmids

I think I might be gay

For young people struggling with issues around their sexuality, 'coming out' to their families, schools and communities can be traumatic. The alarming statistics for youth suicide, risk-taking behaviours and mental health concerns reflect the alienation and harassment felt by gay, lesbian, bisexual and transgendered young people as they wrestle in isolation with the difficulties of 'being different'. They need families, schools and communities to provide support, understanding and affirmation; and to be their allies against homophobia. Maria Pallotta-Chiarolli has compiled a valuable guide for all those whose lives are affected by a young person coming out. In this work she includes first-hand accounts from families, schools and communities across different socioeconomic levels, diverse regions and many cultural backgrounds. She also provides vital suggestions and advice for those at the coalface of this issue - parents of young people who need to come out, high-school teachers and community leaders - as well as effective responses and strategies for dealing with homophobia in any environment

The Ambiguous Taxation of Prostitution: the Role of Fiscal Arrangements in Hindering the Sexual and Economic Citizenship of Sex Workers

This article explores the understudied and undertheorized role that fiscal policies play in shaping the relationship between the state and sex workers. It highlights the importance of looking at tax policy and its implementation to understand how inequality is reinforced against sexually marginalized populations. Drawing on the Italian case, it explores the ways in which ambiguous taxation arrangements operate to penalize sex workers, excluding them from the status of full taxpayer citizenship, and demonizing them as individuals who exploit the fiscal system at the expense of “good” tax-paying citizens. Fiscal policies, I argue, need to be considered in the context of the governance of prostitution as social mechanisms that have the potential to contribute to the sexual and economic citizenship of this marginalized population, but which, when unequal and ambiguous, reinforce the social and political liminality of sex workers as lesser citizens, and add to the stigma, damaging stereotypes and violence already waged against them. The complex ways in which inequality against sex workers is maintained is revealed as a dynamic process that reflects the ever-shifting interplay of economics and morality

Student and Instructor Attitudes Toward 21st Century Writing Technologies in the Rural Secondary English Classroom

This thesis focuses on how students and teachers feel about the current use of technologies like Chromebooks and laptops in the rural secondary English classroom. Chapter one describes my personal journey as a student and educator using various technologies in the classroom, and how I came upon the idea for this study while observing one of the first high schools to implement full 1:1 Chromebook technology in the United States. Then, I discuss my review of the current literature on the subject, and find that there is a lack of knowledge about the emergence of these types of technologies, and the impact they may have on the educational setting previously noted. In an attempt to better understand these attitudes held by students and teachers, I conducted my research by observing two English 9 classes, during two separate lessons, that normally use Chromebooks. To find out if the attitudes about technology were directly related to the lessons, I had one class use the Chromebooks for one of the lessons, and the other class refrained from using the computers for both lessons. Next, I created a questionnaire that asked about the use of technology in the classroom and how it related to their perceived opinion of the lessons, and analyzed the responses. Also, I created a questionnaire to ask the teacher about her opinion of the Chromebooks and how they may have affected the lessons. As a final attempt to gather as much information as I could about these student attitudes, I administered two focus groups, one from each class, comprised of eight total students. Chapter three goes into detail analyzing the responses from the students and teacher. What I found was that I did not sufficiently answer my original thesis questions with the student questionnaire, but realized that the attitudes held by students regarding the Chromebooks came out during the focus group discussions instead. During these discussions students talked about how they preferred paper and pen to the Chromebooks, handwriting as opposed to typing on the computers, and the multitude of technical issues that come with using the laptops. This directly opposed the teacher\u27s attitude in that she believed students preferred using the Chromebooks, and that they were much more efficient than traditional methods of writing. My conclusion based on these findings is that the teachers and administrators must give the students using technology in a rural high school setting a platform to discuss their honest opinions. This platform could be a technology committee or subset of an existing committee like student council that allows for open discussion of the use of technology in the school

Lifestyle behaviours, psychological wellbeing and cardiovascular disease in women executives and senior management

A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Arts Masters (Industrial/ Organisational Psychology) in the Faculty of Humanities, University of the Witwatersrand, Johannesburg. March, 2016This study investigated whether the lifestyle behaviours and psychological well-being of women executives and managers predicted their ten-year risk of developing cardiovascular disease. The sample of South African women executives and managers work in a variety of industries in the cities of Johannesburg, Durban and Cape Town. The study sought to determine the predictability of the women executives and managers’ risk of developing cardiovascular disease through examining their level of alcohol consumption, level of physical exercise and the nutritional and dietary choices that they made as well as their level of depression, anxiety and stress. The data was gathered through an executive health and wellness programme and logistic regression and Chi-squared tests of association were used in conducting the analyses. The results suggested that the level of alcohol consumption and the nutritional and dietary choices made were predictive of the individual’s ten-year risk of developing cardiovascular disease. Additionally, the level of anxiety was found to be associated with the risk of developing cardiovascular disease. The results suggest that both individuals and organisations should prioritise the changing of unhealthy lifestyle behaviours, specifically excessive alcohol consumption and daily dietary choices, in order to lower their risk of developing cardiovascular disease.MT201

Mental Health

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