Physicochemical complexity in complex chemical systems

Self-replication and compartmentalization are two central properties thought to be essential for minimal life, and understanding how such processes interact in the emergence of complex reaction networks is crucial to exploring the development of complexity in chemistry and biology. Autocatalysis can emerge from multiple different mechanisms such as formation of an initiator, template self-replication and physical autocatalysis (where micelles formed from the reaction product solubilize the reactants, leading to higher local concentrations and therefore higher rates). Amphiphiles are also used in artificial life studies to create protocell models such as micelles, vesicles and oil-in-water droplets, and can increase reaction rates by encapsulation of reactants. So far, no template self-replicator exists which is capable of compartmentalization, or transferring this molecular scale phenomenon to micro or macro-scale assemblies. Here a system is demonstrated where an amphiphilic imine catalyses its own formation by joining a non-polar alkyl tail group with a polar carboxylic acid head group to form a template, which was shown to form reverse micelles by Dynamic Light Scattering (DLS). The kinetics of this system were investigated by 1H NMR spectroscopy, showing clearly that a template self-replication mechanism operates, though there was no evidence that the reverse micelles participated in physical autocatalysis. Active oil droplets, composed from a mixture of insoluble organic compounds in an aqueous sub-phase, can undergo processes such as division, self-propulsion and chemotaxis, and are studied as models for minimal cells, or protocells. Although in most cases the Marangoni effect is responsible for the forces on the droplet, the behaviour of the droplet depends heavily on the exact composition. Though theoretical models are able to calculate the forces on a droplet, to model a mixture of oils on an aqueous surface where compounds from the oil phase are dissolving and diffusing through the aqueous phase is beyond current computational capability. The behaviour of a droplet in an aqueous phase can only be discovered through experiment, though it is determined by the droplet's composition. By using an evolutionary algorithm and a liquid handling robot to conduct droplet experiments and decide which compositions to test next, entirely autonomously, the composition of the droplet becomes a chemical genome capable of evolution. The selection is carried out according to a fitness function, which ranks the formulation based on how well it conforms to the chosen fitness criteria (e.g. movement or division). Over successive generations, significant increases in fitness are achieved, and this increase is higher with more components (i.e. greater complexity). Other chemical processes such as chemiluminescence and gelation were investigated in active oil droplets, demonstrating the possibility of controlling chemical reactions by selective droplet fusion. Potential future applications for this might include combinatorial chemistry, or additional fitness goals for the genetic algorithm. Combining the self-replication and the droplet protocells research, it was demonstrated that the presence of the amphiphilic replicator lowers the interfacial tension between droplets of a reaction mixture in organic solution and the alkaline aqueous phase, causing them to divide. Periodic sampling by a liquid handling robot revealed that the extent of droplet fission increased as the reaction progressed, producing more individual protocells with increased self-replication. This demonstrates coupling of the molecular scale phenomenon of template self-replication to a macroscale physicochemical effect.

Staff and students co-creating curricula in UK higher education: exploring process and evidencing value

Student engagement in learning and teaching is receiving a growing level of interest from policy makers, researchers, and practitioners. This includes opportunities for staff and students to co-create curricula, yet there are few examples within current literature which describe and critique this form of staff-student collaboration (Bovill (2013a), Healey et al (2014), Cook-Sather et al (2014). The competing agendas of neoliberalism and critical, radical pedagogies influence the policy and practice of staff and students co-creating curricula and, consequently, attempt to appropriate the purpose of it in different ways. Using case-based research methodology, my study presents analysis of staff and students co-creating curricula within seven universities. This includes 17 examples of practice across 14 disciplines. Using an inductive approach, I have examined issues relating to definitions of practice, conceptualisations of curricula, perceptions of value, and the relationship between practice and institutional strategy. I draw upon an interdisciplinary body of literature to provide the conceptual foundations for my research. This has been necessary to address the complexity of practice and includes literature relating to student engagement in learning and teaching, conceptual models of curriculum in higher education, approaches to evidencing value and impact, and critical theory and radical pedagogies. The study makes specific contributions to the wider scholarly debate by highlighting the importance of dialogue and conversational scholarship as well as identifying with participants what matters as well as what works as a means to evidence the value of collaborations. It also presents evidence of a new model of co-creating curricula and additional approaches to conceptualising curricula to facilitate collaboration. Analysis of macro and micro level data shows enactment of dialogic pedagogies within contexts of technical-rational strategy formation and implementation.