Phylogeography of an Amazonian Cichlid supports strong structuration by water current and past evolution by vicariance associated to the Amazon's formation.

Amazonia is characterized by very heterogeneous riverscapes dominated by two drastically divergent water types: black (ion-poor, dissolved organic carbonate rich and acidic) and white (nutrient rich and turbid) waters. Recent phylogeographic and genomic studies have associated the ecotone formed by these environments to ecologically driven speciation in fish species. With the objective of better understanding the evolutionary forces behind the Amazonian Teleostean diversification, we sampled 240 Mesonauta festivus from 12 sites on a wide area of the Amazonian basin. These sites included three confluences of black and white water environments to seek for repeated evidences of ecological speciation at these ecotones. Our genetic dataset of 41,268 SNPs is contrasting with previous results and supports a low structuring power of water types. Conversely, we detected a strong pattern of isolation by unidirectional downstream water current and evidence of past events of vicariance potentially linked to the Amazon River formation and salt-water incursions that occurred 2.5 Mya. Using a combination of population genetic, phylogeographic analysis and environmental association models, we decomposed the spatial variance from the environmental genetic variance specifically to assess which evolutive forces have shaped inter-population differences in M. festivus’ genome. Our sampling design comprising four major Amazonian rivers and three confluences of black and white water rivers supports the possibility that past studies potentially confounded ecological speciation with a site effect unrepresentative of the full Amazonian watershed. While ecological speciation admittedly played a role in Amazonian fish species diversification, we argue that neutral evolutionary processes explain most of the divergence between M. festivus populations.

When Technologies are Not Enough: The Challenges of Digital Interventions to Address Loneliness in Later Life

This article discusses sociotechnical challenges of technology-based interventions to address loneliness in later life. We bring together participatory and multidisciplinary research conducted in Canada and Australia to explore the limits of digital technologies to help tackle loneliness among frail older people (aged 65+). Drawing on three case studies, we focus on instances when technology-based interventions, such as communication apps, were limiting or failed, seeming to enhance rather than lessen loneliness. We also unpack instances where the technologies being considered did not match participants’ social needs and expectations, preventing adoption, use, and the intended outcomes. To better grasp the negative unintended consequences of these technological interventions, we combine a relational sociological approach to loneliness with the Strong Structuration Theory developed by sociologist Rob Stones. This combined lens highlights the connection between sociotechnical factors and their agentic and structural contexts, facilitating a rich understanding of why and when technologies fail and limit.

Understanding political accountability in a strong structuration framework

PurposeResearch was conducted to investigate whether, and how, political accountability might stabilise when agents are faced with profound changes in external structures such as competition laws and austerity policies.Design/methodology/approachWe performed a field study from 2007 to 2015 in a regional hub in Finland and worked with data from document analysis, interviews and meeting observations. We have used embedded research design, where we apply methodological bracketing as well as composite sequence analysis for field research.FindingsAccountability declined when irresistible external structures were the dominant influence on the unreflective actions of agents-in-focus. With time, however, the agents started acting critically by drawing on structures that could facilitate strategic actions to stabilise political accountability.Research limitations/implicationsThe field research and interpretation of the data were limited to the organisation analysed; however, the theoretical arguments allow for analytical generalisations.Practical implicationsThe research demonstrates how public officials and political decision-makers can eventually adopt a strategic approach when faced with irresistible change in external structures.Social implicationsThe research demonstrates how public officials and political decision-makers can eventually adopt a strategic approach when faced with irresistible changes in external structures.Originality/valueThe study locates political accountability in the context of strong structuration theory and discusses how it is redefined by external structures.

Transferable Gaussian Attractive Potentials for Organic/oxide Interfaces

Organic/oxide interfaces play an important role in many areas of chemistry, and in particular for lubrication and corrosion. Molecular dynamics simulations are the method of choice for providing complementary insight to experiments. However, the force fields used to simulate the interaction between molecules and oxide surfaces tend to capture only weak physisorption interactions, discarding the stabilizing Lewis acid/base interactions. We here propose an improvement of the usual molecular mechanics description (based on Lennard-Jones and electrostatic interactions) by addition of an attractive Gaussian potential between reactive sites of the surface and heteroatoms of adsorbed organic molecules, leading to the GLJ potential. The interactions of four oxygenated and four amine molecules with the typical and widespread hematite and γ-alumina surfaces are investigated. The total RMSD for all probed molecules decreases from 29.2 to 5.7 kcal/mol, and the corresponding percentage from 107.4 to 22.6% over hematite, while on γ-alumina the RMSD decreases from 21.5 to 7.6 kcal/mol, despite using a single parameter for all five chemically inequivalent surface aluminum atoms. Applying GLJ to the simulation of n-octadecanamine and N-tetradecyldiethanolamine adsorbed films on hematite and alumina respectively demonstrates that mobility of the surfactants is overestimated by the common LJ potential, while GLJ shows a strong structuration and slow dynamics of the surface films, as could be expected from the first-principles adsorption energies for model head-groups.

Transferable Gaussian Attractive Potentials for Organic/oxide Interfaces

Organic/oxide interfaces play an important role in many areas of chemistry, and in particular for lubrication and corrosion. Molecular dynamics simulations are the method of choice for providing complementary insight to experiments. However, the force fields used to simulate the interaction between molecules and oxide surfaces tend to capture only weak physisorption interactions, discarding the stabilizing Lewis acid/base interactions. We here propose an improvement of the usual molecular mechanics description (based on Lennard-Jones and electrostatic interactions) by addition of an attractive Gaussian potential between reactive sites of the surface and heteroatoms of adsorbed organic molecules, leading to the GLJ potential. The interactions of four oxygenated and four amine molecules with the typical and widespread hematite and γ-alumina surfaces are investigated. The total RMSD for all probed molecules decreases from 29.2 to 5.7 kcal/mol, and the corresponding percentage from 107.4 to 22.6% over hematite, while on γ-alumina the RMSD decreases from 21.5 to 7.6 kcal/mol, despite using a single parameter for all five chemically inequivalent surface aluminum atoms. Applying GLJ to the simulation of n-octadecanamine and N-tetradecyldiethanolamine adsorbed films on hematite and alumina respectively demonstrates that mobility of the surfactants is overestimated by the common LJ potential, while GLJ shows a strong structuration and slow dynamics of the surface films, as could be expected from the first-principles adsorption energies for model head-groups.

Strengthening friendship and pursuing artist dreams by informal musical practices: Musical agency in a cross-cultural context

This article builds upon an ethnographic study of how young people growing up in cross-cultural contexts perform their musical agency (Strøm, 2016). The twofold focus of the article concerns the ways in which the pop duo GunnInga perform their collective musical agency as well as how they strengthen their friendship and fulfill their artist dreams through informal musical practices. The theoretical framework of the article builds upon Stones’s (2005) strong structuration theory. The analysis is structured using Karlsen’s (2011) musical agency lens as a point of departure. In line with Liamputtong’s (2010) request to cross-cultural researchers, the analysis also applies a poem as an analytical tool. The term cross-cultural is applied to situate the pop duo in a context characterized by diversity in terms of both nationalities and options when it comes to activities, concerts, projects, workshops and so on, offered by both municipal and private cultural agents attempting to respond to this reality.

Understanding the multiple health system and contextual barriers to hypertension control: Towards a new framework and its application to the Philippines

Reducing the burden of CVD is critically important, especially among poor individuals in in LMICs, where the treatment gap is widest. In order to address this inequity, evidence is needed on the experiences of economically marginalised individuals in LMICs diagnosed with CVDs. At present, there is little focus on the experiences of such individuals as they make sequential decisions regarding their care over time. Moreover, the evidence base is hampered by the lack of a clear framework encapsulating both individual agency and societal structures in conceptualising this chronology of behaviour. We aim to address this gap by capturing patient pathways of individuals diagnosed with hypertension in Malaysia and the Philippines drawing on a framework informed by strong structuration theory (SST). This lens allows examination of the social, economic and environmental forces that influence accessibility and quality of health services available to low-income residents in LMICs.