Composition dependent magnetic properties of iron oxide - polyaniline nanoclusters

Gamma - Iron Oxide prepared by sol -gel process was used to produce nanocomposites with polyaniline of varying aniline concentrations. TEM shows the presence of chain like structure for lower polyaniline concentration. The room temperature hysteresis curves show finite coercivity of 160 Oe for all the composites while the saturation magnetization was found to decrease with increasing polymer content. ZFC - FC magnetisation measurements indicate high blocking temperatures. It is believed that this indicates a strongly interacting system, which is also shown by our TEM results. Monte Carlo simulations performed on a random anisotropy model with dipolar and exchange inteactions match well with experimental results.Comment: 9 (nine) pages, 6 figures (jpeg and eps

A decrease in iron availability to human gut microbiome reduces the growth of potentially pathogenic gut bacteria: an in vitro colonic fermentation study

Iron-supplements are widely consumed; however most of the iron is not absorbed and enters the colon where potentially pathogenic bacteria can utilise it for growth. This study investigated the effect of iron availability on human gut microbial composition and function using an in vitro colonic fermentation model inoculated with faecal microbiota from healthy adult donors, as well as examining the effect of iron on the growth of individual gut bacteria. Batch fermenters were seeded with fresh faecal material and supplemented with the iron chelator, bathophenanthroline disulphonic acid (BPDS). Samples were analysed at regular intervals to assess impact on the gut bacterial communities. The growth of Escherichia coli and Salmonella Typhimurium was significantly impaired when cultured independently in iron-deficient media. In contrast, depletion of iron did not affect the growth of the beneficial species, Lactobacillus rhamnosus, when cultured independently. Analysis of the microbiome composition via 16S-based metataxonomics indicated that under conditions of iron chelation, the relative abundance decreased for several taxa, including a 10% decrease in Escherichia and a 15% decrease in Bifidobacterium. Metabolomics analysis using 1 HNMR indicated that the production of SCFAs was reduced under iron-limited conditions. These results support previous studies demonstrating the essentiality of iron for microbial growth and metabolism, but, in addition, they indicate that iron chelation changes the gut microbiota profile and influences human gut microbial homeostasis through both compositional and functional changes

Saving our Sisters: Critical inquiry into sex trafficking discourses and interventions in the Philippines

This research critiques the Philippine anti-trafficking sector’s conflation of sex work with victimhood and shows that this conflation is inconsistent with the lived realities of many sex workers. It examines the politics of knowledge production in the anti-trafficking sector and posits that the exclusion of sex workers from policymaking conversations is a form of epistemic injustice. Using a framework that foregrounds sex workers’ speech practices, self-representations, and reflections on their own work, it demonstrates that there was a mixture of choice and coercion in my interviewees’ engagement with sex work, but that they were not victims in need of ‘rescuing’ through the criminal justice system. Sex work was better than their realistic alternatives and allowed them to contest their displacement in the labour market and resist gendered low-paid and labour-intensive jobs such as sewing and domestic work. Social stigma undermined their esteem, self-worth, and ability to exercise agency, but they also reworked social scripts by distinguishing their work as clean and honest, in contrast to the hypocrisy of ‘moral entrepreneurs’. Partially as a reactive form of self-construction, many saw their engagement in sex work as a moral project, through which they demonstrated virtue as mothers and daughters. Some saw themselves as entrepreneurial, capitalising on their attractiveness and the male demand for sex. Some, indeed, saw themselves as victims. However, close attention to their rendering of the word ‘victim’ reveals that they saw themselves as victims of poverty, stigma, and policies and practices that removed their control over their working conditions and exposed them to extortion and abuse. Instead of raids and rehabilitation, they wanted political agency and recognition. Based on these findings, I propose approaching sex work from a labour rights and social justice lens rather than full or partial criminalisation. This research also engages with broader conversations on methodological issues in feminist social research, especially around ethical ways of establishing trust with stigmatised populations, treating sex workers as partners in knowledge production while still preserving a critical distance for academic reflection, and negotiating research decisions with gatekeepers.Gates Scholarshi

The impact of iron on the function and composition of the human gut microbiota

Iron-supplements are widely consumed; however, most of the iron is not absorbed and enters the colon where potentially pathogenic bacteria can utilise it for growth. Assessing iron bioavailability and the effects on bacterial groups is an evolving subject area and forms the basis of the research presented in this thesis. The growth of Escherichia coli and Salmonella Typhimurium was significantly impaired when cultured independently in iron-deficient media (p<0.0001). These observations positively correlated with a decrease in water-soluble iron concentrations present in the culture. However, depletion of iron did not affect the growth of the beneficial species, Lactobacillus rhamnosus. Culturing human faecal microbiotas in an in vitro colon model identified changes in the growth of different bacterial taxa. 16S rDNA-based metataxonomics indicated that under conditions of iron depletion through BPDS, a chemical iron chelator, the relative abundance of several taxa decreased, including a 10% and 15% decrease in Escherichia and Bifidobacterium, respectively. This was supported by observations of lower viable counts of Enterobacteriaceae and bifidobacteria. Analysis using 1H NMR indicated that the production of acetate, butyrate and propionate in vitro was reduced under iron-restricted conditions. Iron chelation through phytin, a dietary compound, illustrated similar results with the exception of a 33% increase in the relative abundance of Bifidobacterium and 225% increase in Collinsella. Furthermore, increases in propionate and formate concentrations were also observed when cultured with phytin. A 6-week, crossover double-blinded randomised human dietary intervention trial was performed (n=14), where participants were asked to consume encapsulated phytin or placebo. Capsules were coated with a specialised formulation, Phloral®, designed to release phytin directly in the colon. No conclusions could be made regarding the iron chelating properties of phytin as analysis of stool samples collected revealed clumps of phytin and therefore, unsuccessful dispersal of phytin within the colonic lumen. This pilot human intervention study indicates that the form of phytin is an important factor and this should be considered for follow-up studies

Mapping the Path to Philippine Reproductive Rights Legislation: Signs of Progress Amidst Obstacles

While the Philippines is a signatory to multiple international conventions that affirm women’s reproductive rights, attempts to enact legislation to promote a comprehensive national framework for modern family planning and evidence-based sex education have been thwarted by Catholic bishops, lay groups, and conservative politicians for over a decade. Partially as a result of this, the Philippines’ reproductive health indicators are dismal relative to its neighbors’. This paper examines the debates around the Reproductive Healthcare law, whose constitutionality is currently being challenged by conservative groups in the Philippine Supreme Court, and the bargaining processes that characterized the passage of the law. Finally, it identifies the threats and opportunities of the existing law and the dangers of a Supreme Court reversal

Regulating motherhood through markets: Filipino women’s engagement with microcredit

The Philippines is a global leader in deploying microcredit to address poverty. These programmes are usually directed at women. Research on these programmes focuses on traditional economic indicators such as loan repayment rates but neglects impacts on women’s agency and well-being, or their position in the household and relationships with their partners and children. It is taken for granted that access to microcredit leads to enhanced gender freedoms. In line with the growing body of work in feminist scholarship that critiques the instrumentalist logic of microfinance institutions (MFIs) in relation to women, this research foregrounds stories from interviews with female borrowers in Zamboanga City in Southern Philippines to provide grounded illustrations of how microcredit is reshaping relationships between women and their families, women and poverty and women and the state. Borrowers used loans to meet their family’s needs even at the cost of harassment from creditors, indebtedness, increased workloads and conflict with partners. These narratives challenge the dominant neoliberal discourse of female empowerment through access to credit by exposing how microcredit is part of a complex set of regulations around ‘good motherhood’ and consumption, where women’s moral worth is based on their willingness and ability to lift their families out of poverty