Structural Studies of Surfactants at Interfaces

PhDThis thesis consists of a collection of studies on surfactant adsorption at different interfaces. Particularly, this dissertation focuses on adsorption processes occurring at buried interfaces (solid-liquid and liquid-liquid). Because of complexity in the sample environment, the study of buried interfaces is experimentally challenging. Neutron reflectivity enables the study of adsorption processes at interfaces at atomic length scale. Furthermore, neutrons can be transmitted through solid substrates, permitting the analysis of buried interfaces. The technique was used to describe adsorption processes both qualitatively and quantitatively, delivering information regarding structure of adsorbed layers and adsorbed amount. Different investigations were carried out during the PhD and the results are grouped into two main sections. Investigations at the solid-liquid interface are presented in the first section. Chapter 3 provides an example of structural study of complex multi-layers at the silicon-water interface; a surfactant adsorption study at the technologically relevant metal-oil interface is presented in Chapter 4. The second section discusses a series of neutron reflectivity experiments at the important oil-water interface. The structural study of a series of non-ionic dodecanol ethoxylate surfactants is discussed in Chapter 6. The structure of a lipid monolayer as model for a biological membrane is reported in Chapter 7. Chapter 8 is a comparative study of fatty acid-alkylated azacrown ether co-adsorption at the air-water and oil-water interface. These mixtures are used for metal ion extraction processes. This was the first analysis of a surfactant mixture at the oil-water interface using neutron reflectivity. Some of the studies reported here are the first of their kind and the advances affect different technologically and biologically relevant areas. As a result of this PhD project a number of follow-up studies have been planned and several neutron reflectivity experiments will be performed in the future to further explore these interesting areas of science

#dadtribe: Performing Sharenting Labour to Commercialise Involved Fatherhood

This study looks at commercial representations of fatherhood within macromarketing. We base our study on ‘Instadads,’ a group of father influencers who use Instagram to document their family lives, and foster a following that is attractive to brand sponsorship. Through a netnography of 21 Instadad accounts and 10 in-depth interviews, we investigate how these influencers perform sharenting labour, which is the labour involved in commodifying and monetising the sharing of parental experiences. We posit that through this labour, father influencers contribute to early attempts at translating the new discursive territory of involved fatherhood into mainstream commercial representations. Sharenting labour has the potential to shift discourses on masculinities, lending more legitimacy to male parental caregiving activities

Introduction to the Special Issue: A Macromarketing Perspective on Alternative Economies

Alternative economies respond to the precarious conditions underpinning the everyday lives of individuals, and their lack of access to and scarcity of resources and competences. Recently there has been increasing interest in the field of macromarketing towards such alternative forms of exchange and marketplaces. Nonetheless, current understandings of alternative economies remain fragmented. The objective of this special issue is to advance our understanding of alternative economies and stimulate future research within this domain. Seven articles are included in this special issue of the Journal of Macromarketing. Each article presents forward-looking research exploring one of three aspects of alternative economies: (1) the paradigms used within alternative economies, (2) the institutional logics that guide action within these systems and (3) the implications to individuals, localities, markets, and society. The editors of the special issue briefly introduce the topic, provide a definition of alternative economies, offer an overview of the articles and their contributions, and direction for future research bringing together alternative economies and macromarketing

Nonconvulsive Seizures and Dementia: A Case Report

Nonconvulsive status epilepticus (NCSE) is a severe medical condition that shows increased incidence in the elderly and is frequently underdiagnosed because of its pleomorphic presentation. We report an NCSE in a 76-year-old woman affected by dementia with acute change of cognitive status and behavior. Intravenous diazepam solved clinical and electroencephalographic manifestations. Neuropsychological assessment after NCSE conclusion showed impairment of several fields that remained unchanged at 3-month followup. NCSE should be considered when sudden and transient cognitive fluctuations appear in the elderly. Epileptic events in dementia occur frequently and are often underrecognized; this could be a misleading factor when considering a quick progression of mnesic performances. Moreover, recent findings both in animal models and in humans demonstrated the deep link between epilepsy and dementia, also supporting the hypothesis that epileptiform activity could contribute to cognitive impairment

E-learning for research capacity strengthening in sexual and reproductive health: the experience of the Geneva Foundation for Medical Education and Research and the Department of Reproductive Health and Research, World Health Organization

Abstract: Technological advancement has resulted in the increasing use of e-learning and online education, initially in high-income countries and increasingly in low- and middle-income countries. Background: In 2010, the Geneva Foundation for Medical Education and Research, in collaboration with the World Health Organization and partner institutions, developed an online postgraduate course “From Research to Practice: Training Course in Sexual and Reproductive Health Research”. This course takes advantage of the advancing Internet technology to provide training opportunities to health professionals mostly from low- and middle-income countries whose access to quality education is constrained by time, financial resources, or both. Case presentation: To assess the outcomes of the course, an evaluation was conducted by sending a self-administered questionnaire to graduates of the 2010–2012 programme. The objectives were to determine if the graduates had applied the knowledge gained from the course to their work and whether they had implemented their research project developed during the course. The evaluation also appraised the number of graduates who participated in the design or implementation of a new research project since the course concluded and whether the course had contributed to advancement in their careers. A total of 175 of 219 course graduates answered the questionnaire. The evaluation revealed that the majority of respondents (98%) had utilized the knowledge acquired, with nearly half of them (47%) having published a scientific paper as author or co-author. About a third of respondents (39%) had implemented their course research project and about three quarters of them (74%) have been involved in the design or implementation of a research project after completing the course. Over three quarters (81%) of respondents opined that the course had contributed to their career advancement and almost half of them (46%) had a career promotion as a direct or indirect benefit of the course. Conclusion: We surmise that the course positively impacted the participants’ knowledge and understanding of sexual and reproductive health, which they applied in their professional work, as well as strengthened their research capacity. Success factors for the e-learning programme include tailor-made content to meet participants’ needs, flexibility of access, and ongoing engagement/personal interactivity with course coaches

Long-Term Outcome and Risk Stratification in Dilated Cardiolaminopathies

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PEGylation affects the self-assembling behaviour of amphiphilic octapeptides

Surfactant-like peptides are a class of amphiphilic macromolecules, which are able to self-assemble in water forming different supramolecular structures. Among them, octapeptides composed of six hydrophobic and two hydrophilic residues have attracted interest since they have a length similar to those of natural phospholipids. Supramolecular structures of different amphiphilic octapeptides have been widely reported, but no study has been performed aimed at investigating the effect of PEGylation on their self-assembling behaviour. The aim of the present work was to synthesize and characterise the self-assembling behaviour of PEGylated alanine- or valine based amphiphilic octapeptides (mPEG1.9kDa-DDAAAAAA and mPEG1.9kDa-DDVVVVVV) in comparison to the non-PEGylated ones (DDAAAAAA and DDVVVVVV). The self-aggregation process in ultrapure water was investigated by fluorescence spectroscopy, small angle neutron scattering (SANS), dynamic light scattering (DLS), while the secondary structure was assessed by circular dichroism. PEGylation markedly affects the self-assembling behaviour of these amphiphilic octapeptides in terms of both critical aggregation concentration (CAC) and shape of the formed supramolecular aggregates. Indeed, PEGylation increases CAC and prevents the self-aggregation into fibrillary supramolecular aggregates (as observed for non-PEGylated peptides), by promoting the formation of micelle-like structures (as demonstrated for valine-based octapeptide). On the other side, the secondary structure of peptides seems not to be affected by PEGylation. Overall, these results suggest that self-assembling behaviour of amphiphilic octapeptides can be modified by PEGylation, with a great potential impact for the future applications of these nanomaterials