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The stability of a granular material is a collective phenomenon controlled by individual particles through their interactions. Forecasting when granular materials will undergo an abrupt failure is an ongoing challenge due to the intricate interactions between particles. Here, we report experiments on photoelastic disks undergoing intermittent stick-slip dynamics in a quasi-2D annular shear apparatus, with the evolving network of contact forces made visible via polarized light. We characterize the system by interpreting the interparticle forces as a multilayer network, and apply GenLouvin community detection to identify strongly correlated groups of particles. We observe that the community structure becomes increasingly volatile as the material approaches failure, and that this volatility provides a forecast that precedes what is detectable by considering the forces alone. We additionally observe that both weak and strong forces contribute to the strength of this forecast. These findings provide a new approach to detect patterns of causality and forecast impending failures.

Granular media are soft matter systems that exhibit some of the extreme behavior of complex fluids. Understanding of the natural formation of planetary bodies, landing on and exploring them, future engineering of structures beyond Earth and planetary defense all hinge on the ability to predict the complex mechanical behavior of granular matter. As we understand them, these behaviors are linked to the granular fluid to solid transition. In this white paper, we describe issues that emerge for granular systems under reduced gravity and their implications for basic science and space exploration. (Topical White Paper submitted to the NASA Biological and Physical Sciences in Space Decadal Survey 2023-2032), arXiv admin note: text overlap with arXiv:1002.2478

Boundary shape, particularly roughness, strongly controls the amount of wall slip in dense granular flows. In this paper, we aim to quantify and understand which aspects of a dense granular flow are controlled by the boundary condition, and to incorporate these observations into a cooperative nonlocal model characterizing slow granular flows. To examine the influence of boundary properties, we perform experiments on a quasi-2D annular shear cell with a rotating inner wall and a fixed outer wall; the later is selected from among 6 walls with various roughness, local concavity, and compliance. We find that we can successfully capture the full flow profile using a single set of empirically determined model parameters, with only the wall slip velocity set by direct observation. Through the use of photoelastic particles, we observe how the internal stresses fluctuate more for rougher boundaries, corresponding to lower wall slip, and connect this observation to the propagation of nonlocal effects originating at the wall.

As a result of extreme weather conditions, such as heavy precipitation, natural hillslopes can fail dramatically; these slope failures can occur on a dry day due to time lags between rainfall and pore-water pressure change at depth, or even after days to years of slow-motion. While the pre-failure deformation is sometimes apparent in retrospect, it remains challenging to predict the sudden transition from gradual deformation (creep) to runaway failure. We use a network science method -- multilayer modularity optimization -- to investigate the spatiotemporal patterns of deformation in a region near the 2017 Mud Creek, California landslide. We transform satellite radar data from the study site into a spatially-embedded network in which the nodes are patches of ground and the edges connect the nearest neighbors, with a series of layers representing consecutive transits of the satellite. Each edge is weighted by the product of the local slope (susceptibility to failure) measured from a digital elevation model and ground surface deformation (current rheological state) from interferometric synthetic aperture radar (InSAR). We use multilayer modularity optimization to identify strongly-connected clusters of nodes (communities) and are able to identify both the location of Mud Creek and nearby creeping landslides which have not yet failed. We develop a metric, community persistence, to quantify patterns of ground deformation leading up to failure, and find that this metric increases from a baseline value in the weeks leading up to Mud Creek's failure. These methods promise as a technique for highlighting regions at risk of catastrophic failure., Comment: 10 pages, 7 figures

This paper reports on an analysis of patterns of children’s bodily movements in an Early Years classroom. I illustrate two prevalent patterns identified during close observations of children's walking movements as they as they followed their interests while accessing continuous provision in an Early Years setting in England. I termed the patterned pathways movement/ interest formations and draw a relationship between these formations and affective atmospheres, suggesting that these atmospheres were created by the dynamics and flows of children's ongoing bodily movements. I propose that affective atmospheres and movement/interest formations are intricately connected to child-produced meanings as children re-imagine, re-shape and re-purpose classroom spaces and materials. In this way I contribute to conceptual understandings role of children's whole bodily movements and the accompanying affective atmospheres in the emergence of young children's literacy practices. My findings substantiate viewpoints that children should be provided with the opportunity to engage in exploratory play and move freely in education settings. Furthermore, I suggest that practitioners be attuned to the the affective dimensions of young children's emerging literacy practices in Early Years classrooms.

Agency and its role in the early literacy classroom has long been a topic for debate. While sociocultural accounts often portray the child as a cultural agent who negotiates their own participation in classroom culture and literacy learning, more recent framings draw attention from the individual subject, instead seeing agency as dispersed across people and materials. In this article, I draw on my experiences of following children as they followed their interests in an early literacy classroom, drawing on the concepts of assemblage and people yet to come, as defined by Deleuze and Guattari and Spinoza’s common notion. I provide one illustrative account of moment-by-moment activity and suggest that in education settings it is useful to see activity as a direct and ongoing interplay of three dimensions: children’s moving bodies; the classroom; and its materials. I propose that children’s ongoing movements create possibilities for ‘doing’ and ‘being’ that flow across and between children. I argue that thinking with assemblages can draw attention to both the potentiality and the power dynamics inherent in the ongoing present and also counter preconceived notions of individual child agency and linear trajectories of literacy development, and the inequalities that these concepts can perpetuate within early education settings.

Dense granular systems subjected to an imposed shear stress undergo stick-slip dynamics with systematic patterns of dilation-compaction. During each stick phase, as the frictional strength builds up, the granular system dilates to accommodate shear strain, developing stronger force networks. During each slip event, when the stored energy is released, particles experience large rearrangements and the granular network can significantly change. Here, we use numerical simulations of 3D, sheared frictional packings to show that the mean betweenness centrality -- a property of network of interparticle connections -- follows consistent patterns during the stick-slip dynamics, showing sharp spikes at each slip event. We identify the source of this behavior as arising from the connectivity and contact arrangements of granular network during dilation-compaction cycles, and find that a lower potential for connection between particles leads to an increase of mean betweenness centrality in the system. Furthermore, we show that at high confinements, few particles lose contact during slip events, leading to a smaller change in granular connectivity and betweenness centrality.

While memory effects emerge from systems of wildly varying length- and time-scales, the reduction of a complex system with many interacting elements into one simple enough to be understood without also losing the complex behavior continues to be a challenge. Here, we investigate how bistable cylindrical origamis provide such a reduction via tunably-interactive memory behaviors. We base our investigation on folded sheets of Kresling patterns that function as two-state memory units. By linking several units, each with a selected activation energy, we construct a one-dimensional material that exhibits return-point memory. After a comprehensive experimental analysis of the relation between the geometry of the pattern and the mechanical response for a single bit, we study the memory of a bellows composed of 4 bits arranged in series. Since these bits are decoupled, the system reduces to the Preisach model and we can drive the bellows to any of its 16 allowable states by following a prescribed sequence of compression and extension. We show how to reasonably discriminate between states by measuring the system's total height and stiffness near equilibrium. Furthermore, we establish the existence of geometrically-disallowed defective stable configurations which expand the configuration space to 64 states with a more complex transition pattern. Using empirical considerations of the mechanics, we analyze the hierarchical structure of the corresponding diagram, which includes Garden of Eden states and subgraphs. We highlight two irreversible transformations, shifting and erasure of the defect, leading to memory behaviors reminiscent of those observed with more complex glassy systems., Comment: Submitted to PRResearch

Eutectic gallium-indium (EGaIn), a room-temperature liquid metal alloy, has the largest tension of any liquid at room temperature, and yet can nonetheless undergo fingering instabilities. This effect arises because, under an applied voltage, oxides deposit on the surface of the metal, which leads to a lowering of the interfacial tension, allowing spreading under gravity. Understanding the spreading dynamics of room temperature liquid metals is important for developing soft electronics and understanding fluid dynamics of liquids with extreme surface tensions. When the applied voltage or the oxidation rate becomes too high, the EGaIn undergoes fingering instabilities, including tip-splitting, which occur due to a Marangoni stress on the interface. Our experiments are performed with EGaIn droplets placed in an electrolyte (sodium hydroxide); by placing the EGaIn on copper electrodes, which EGaIn readily wets, we are able to control the initial width of EGaIn fingers, setting the initial conditions of the spreading. Two transitions are observed: (1) a minimum current density at which all fingers become unstable to narrower fingers; (2) a current density at which the wider fingers undergo a single splitting event into two narrower fingers. We present a phase diagram as a function of current density and initial finger width, and identify the minimum width below which the single tip-splitting does not occur.

Fluid droplets can be induced to move over rigid or flexible surfaces under external or body forces. We describe the effect of variations in material properties of a flexible substrate as a mechanism for motion. In this paper, we consider a droplet placed on a substrate with either a stiffness or surface energy gradient, and consider its potential for motion via coupling to elastic deformations of the substrate. In order to clarify the role of contact angles and to obtain a tractable model, we consider a two-dimensional droplet. The gradients in substrate material properties give rise to asymmetric solid deformation and to unequal contact angles, thereby producing a force on the droplet. We then use a dynamic viscoelastic model to predict the resulting dynamics of droplets. Numerical results quantifying the effect of the gradients establish that it is more feasible to induce droplet motion with a gradient in surface energy. The results show that the magnitude of elastic modulus gradient needed to induce droplet motion exceeds experimentally feasible limits in the production of soft solids and is therefore unlikely as a passive mechanism for cell motion. In both cases, of surface energy or elastic modulus, the threshold to initiate motion is achieved at lower mean values of the material properties., 13 pages, 3 figures

The Earth's surface is composed of a staggering diversity of particulate-fluid mixtures: dry to wet, dilute to dense, colloidal to granular, and attractive to repulsive particles. This material variety is matched by the range of relevant stresses and strain rates, from laminar to turbulent flows, and steady to intermittent forcing, leading to anything from rapid and catastrophic landslides to the slow relaxation of soil and rocks over geologic timescales. Geophysical flows sculpt landscapes, but also threaten human lives and infrastructure. From a physics point of view, virtually all Earth and planetary landscapes are composed of soft matter, in the sense they are both deformable and sensitive to collective effects. Geophysical materials, however, often involve compositions and flow geometries that have not yet been examined in physics. In this review we explore how a soft-matter perspective has helped to illuminate, and even predict, the rich dynamics of Earth materials and their associated landscapes. We also highlight some novel phenomena of geophysical flows that challenge, and will hopefully inspire, more fundamental work in soft matter.

Flow-stabilized solids are a class of fragile matter that forms when a dense suspension of colloids accumulates against a semi-permeable barrier, for flow rates above a critical value. In order to probe the effect of particle size on the formation of these solids, we perform experiments on micron-sized monodisperse spherical polystyrene spheres in a Hele-Shaw geometry. We examine the spatial extent, internal fluctuations, and fluid permeability of the solids deposited against the barrier, and find that these do not scale with the P\'eclet number. Instead, we find distinct behaviors at higher Peclet numbers, suggesting a transition from thermal- to athermal-solids which we connect to particle-scale fluctuations in the liquid-like layer at the upstream surface of the solid. We further observe that while the Carman-Kozeny model does not accurately predict the permeability of flow-stabilized solids, we do find a new scaling which predicts the permeability.

Analysis â Sub-themes for theme context (Codes generated from the analysis). (DOCX 16Â kb)

Interview schedule for semi-structured interviews (Table of questions asked to participants). (DOCX 13Â kb)

Granular materials are complex multi-particle ensembles in which macroscopic properties are largely determined by inter-particle interactions between their numerous constituents. In order to understand and to predict their macroscopic physical behavior, it is necessary to analyze the composition and interactions at the level of individual contacts and grains. To do so requires the ability to image individual particles and their local configurations to high precision. A variety of competing and complementary imaging techniques have been developed for that task. In this introductory paper accompanying the Focus Issue, we provide an overview of these imaging methods and discuss their advantages and drawbacks, as well as their limits of application., Comment: Submitted to Review of Scientific Instruments as introduction for: Focus on Imaging Methods in Granular Physics

This chapter examines video recorded interactions of children’s engagement with touchscreens in an early education setting. The extracts are taken from an ethnographic research study that explored children’s expanding repertoires for meaning-making as these emerged throughout their first year of school. The episodes presented in this chapter draw on observations of children’s spontaneous interactions with and around two iPad apps. The findings reveal how children’s engagement with iPads has the potential to simultaneously confer children’s cultural agency and further expand children’s repertoires for meaning-making. The discussion provides nuanced interpretations of how touchscreens might contribute positively to young children’s early learning and play experiences.

For more than two decades, a single model for the spreading of a surfactant-driven thin liquid film has dominated the applied mathematics literature on the subject. Recently, through the use of fluorescently-tagged lipids, it has become possible to make direct, quantitative comparisons between experiments and models. These comparisons have revealed two important discrepancies between simulations and experiments: the spatial distribution of the surfactant layer, and the timescale over which spreading occurs. In this paper, we present numerical simulations that demonstrate the impact of the particular choice of the equation of state (EoS) relating the surfactant concentration to the surface tension. Previous choices of the model EoS have been an ad-hoc decreasing function. Here, we instead propose an empirically-motivated equation of state; this provides a route to resolving some discrepancies and raises new issues to be pursued in future experiments. In addition, we test the influence of the choice of initial conditions and values for the non-dimensional groups. We demonstrate that the choice of EoS improves the agreement in surfactant distribution morphology between simulations and experiments, and impacts the dynamics of the simulations. The relevant feature of the EoS, the gradient, has distinct regions for empirically motivated choices, which suggests that future work will need to consider more than one timescale. We observe that the non-dimensional number controlling the relative importance of gravitational vs. capillary forces has a larger impact on the dynamics than the other non-dimensional groups. Finally, we observe that the experimental approach of using a ring to contain the surfactant could affect the surfactant and fluid dynamics if it disrupts the intended initial surfactant distribution. However, the meniscus itself does not significantly affect the dynamics., 21 pages, 12 figures

A droplet of surfactant spreading on an ultrasoft ($E \lesssim 100$ Pa) gel substrate will produce capillary fractures at the gel surface; these fractures originate at the contact-line and propagate outwards in a starburst pattern. There is an inherent variability in both the number of fractures formed and the time delay before fractures form. In the regime where single fractures form, we observe a Weibull-like distribution of delay times, consistent with a thermally-activated process. The shape parameter is close to 1 for softer gels (a Poisson process), and larger for stiffer gels (indicative of aging). For single fractures, the characteristic delay time is primarily set by the elastocapillary length of the system, calculated from the differential in surface tension between the droplet and the substrate, rather than the elastic modulus as for stiffer systems. For multiple fractures, all fractures appear simultaneously and long delay times are suppressed. The delay time distribution provides a new technique for probing the energy landscape and fracture toughness of ultrasoft materials.

Cholesterol is an essential substance involved in many functions, such as maintaining cell membranes, manufacturing vitamin D on surface of the skin, producing hormones, and possibly helping cell connections in the brain. When cholesterol levels rise in the blood, they can, however, have dangerous consequences. In particular, cholesterol has generated considerable notoriety for its causative role in atherosclerosis, the leading cause of death in developed countries around the world. Homeostasis of cholesterol is centered on the metabolism of lipoproteins, which mediate transport of the lipid to and from tissues. As a synopsis of the major events and proteins that manage lipoprotein homeostasis, this review contributes to the substantial attention that has recently been directed to this area. Despite intense scrutiny, the majority of phenotypic variation in total cholesterol and related traits eludes explanation by current genetic knowledge. This is somewhat disappointing considering heritability estimates have established these traits as highly genetic. Thus, the continued search for candidate genes, mutations, and mechanisms is vital to our understanding of heart disease at the molecular level. Furthermore, as marker development continues to predict risk of vascular illness, this knowledge has the potential to revolutionize treatment of this leading human disease.

Optically-transparent immersion liquids with refractive index (n ~ 1.77) to match sapphire-based aplanatic numerical aperture increasing lens (aNAIL) are necessary for achieving deep 3D imaging with high spatial resolution. We report that antimony tribromide (SbBr$_{3}$) salt dissolved in liquid diiodomethane (CH$_{2}$I$_{2}$) provides a new high refractive index immersion liquid for optics applications. The refractive index is tunable from n = 1.74 (pure) to n = 1.873 (saturated), by adjusting either salt concentration or temperature; this allows it to match (or even exceed) the refractive index of sapphire. Importantly, the solution gives excellent light transmittance in the ultraviolet to near-infrared range, an improvement over commercially-available immersion liquids. This refractive index matched immersion liquid formulation has enabled us to develop a sapphire-based aNAIL objective that has both high numerical aperture (NA = 1.17) and long working distance (WD = 12 mm). This opens up new possibilities for deep 3D imaging with high spatial resolution.

Entropy is a difficult concept to teach using real-world examples. Unlike temperature, pressure, volume, or work, it's not a quantity which most students encounter in their day-to-day lives. Even the way entropy is often qualitatively described, as a measure of disorder, is incomplete and can be misleading. In an effort to address these obstacles, we have developed a simple laboratory activity, the stretching of an elastic rubber sheet, intended to give students hands-on experience with the concepts of entropy, temperature and work in both adiabatic and quasistatic processes. We present two versions of the apparatus: a double-lever system, which may be reproduced with relatively little cost, and a commercial materials testing system, which provides students experience with scientific instrumentation that is used in research., Comment: Submitted to the American Journal of Physics

This paper discusses the ways in which young children collaboratively use narrative play and the available space and materials around them in order to exert cultural agency. The collaborative creation of texts is asserted as central to this expression of agency. By presenting an illustrative vignette of a group of 5-year-old boys as they engage in literacy practices and create a range of meaningful texts within an early years compulsory education setting, the ways in which agency is expressed through the collaborative venture of text creation is explored. The vignette follows an episode of self-initiated dramatic play, fuelled by the children's desire to engage in peer culture and make meanings collaboratively. This play episode spurs the creation of a range of hybridised texts, which culminate in the production of a written narrative. Observations from this study are then used to add to a broader discussion, which raises concerns about the current policy in England, which views early writing development as a set of individual and predefined set of skills to be acquired, a view which could undervalue the experiences that children bring to early educational settings

Thermal fluctuations, geometric exclusion, and external driving all govern the mechanical response of dense particulate suspensions. Here, we measure the stress-strain response of quasi-two-dimensional flow-stabilized microsphere heaps in a regime in which all three effects are present using a microfluidic device. We observe that the elastic modulus and the mean interparticle separation of the heaps are tunable via the confining stress provided by the fluid flow. Furthermore, the measured stress-strain curves exhibit a universal nonlinear shape which can be predicted from a thermal van der Waals equation of state with excluded volume. This analysis indicates that many-body interactions contribute a significant fraction of the stress supported by the heap.

Granular segregation is ubiquitous in industrial, geological or daily-life context, but there is still no unifying theoretical approach. In this review, we examine two examples of granular segregation -- shallow rapid flows and rotating drums -- which suggest that the dynamics of systems at intermediate and high density might be amenable to a statistical mechanics approach.

Aim: The overall aim is to assess the appropriateness of Lay Health Worker (LHW)programmes as a public health intervention in South Africa by considering the effectivenessof LHW programmes across the world and the experience of LHW programmeimplementation and policy making in South Africa. Methods: This thesis comprises 4 papers that explore the issue of LHWs: (I) A systematicreview of randomised controlled trials (RCTs) of LHW interventions in primary andcommunity health care for maternal and child health and the management of infectiousdiseases; (II) A study of the experiences of farm dwellers trained to be LHWs, as exploredthrough focus group discussions; (III) A study of three LHW supervisors who worked on anintervention to support infant feeding mothers, as explored through individual interviews;and (IV) A study of the process of LHW policy development from the perspective of 11 keyinformants who were individually interviewed. Findings: LHWs were found to be effective in promoting breastfeeding and in improvingpulmonary TB cure rates (I). There was also some indication that LHWs could be effective inreducing child morbidity and child and neonatal mortality, and in increasing the likelihood ofcaregivers seeking care for childhood illness (I). The experience of LHWs and LHWsupervisors suggests that LHW programmes need adequate support and supervision,especially in protecting the LHWs themselves (II, III). The care and protection of LHWs wasconsidered by policy makers (IV), but policy redevelopment processes did not link the needto ensure that LHWs were not exploited to concerns about gender exploitation. Conclusions: LHW interventions can be effective but implementing them in developingcountries such as South Africa needs to be approached with caution

Understanding granular and other athermal systems requires the identification of state variables which consistently predict their bulk properties. A promising approach has been to draw on the techniques of equilibrium statistical mechanics, but to consider alternate conserved quantities in place of energy. The Edwards ensemble, based on volume conservation, provides a temperaturelike intensive parameter called compactivity. We present experiments which demonstrate the failure of compactivity to equilibrate (via volume-exchange) between a pair of externally-agitated granular subsystems with different material properties. Nonetheless, we identify a material-independent relationship between the mean and fluctuations of the local packing fraction which forms the basis for an equation of state. This relationship defines an intensive parameter that decouples from the volume statistics., 4 pages, 4 figures, submitted to PRL

Dagstuhl Seminar 07112 took place from Wednesday, 14th March, 2007 to Friday, 16th March. There were 17 participants from a total of 9 different countries. The seminar was led by Graham Kendall and Karen Daniels. Jan van der Veen was designated to collate the proceedings.

From 13.03. to 16.03.2007, the Dagstuhl Seminar 07112 ``Cutting, Packing, Layout and Space Allocation'' was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available.

Background: The literature suggests that although the idea of using evidence to inform policy making has come into favour, actualising this idea in practice is complex. Within the framework of these debates this dissertation focuses on the uptake of findings from research into policy making for the use of magnesium sulphate in the treatment of eclampsia and pre-eclampsia within South Africa. Despite the publication over the past decade of evidence suggesting the effectiveness of magnesium sulphate as a treatment for eclampsia and pre-eclampsia, eclampsia remains a leading cause of maternal death in South Africa and in many other low and middle-income countries. This dissertation forms part of a larger study investigating the uptake of research into policy making in South Africa, Mozambique and Zimbabwe. Aim: To describe and analyse the actual and perceived utilisation of research information in policy making and guideline development for the use of magnesium sulphate in the treatment of eclampsia and pre-eclampsia. Methods: This qualitative study triangulated three techniques in order to understand research utilisation in contemporary policy making. The techniques employed were: policy document review, a historical overview and individual qualitative interviews with 15 key informants. Data generated through these methods are reflected upon in relation to each other and within the context of relevant scientific and intellectual debates. Findings: This study shows a positive example of research utilisation in policy making and guideline development. In the late 1990's in South Africa, prompted by factors such as the recent political change, policies and management guidelines were being developed for maternal health. Simultaneously evidence from randomized controlled trials and systematic reviews showed the effectiveness of magnesium sulphate for the treatment of eclampsia and pre-eclampsia. Policies developed during this period make explicit reference to the use of the most recent published evidence. The uptake of this evidence into national policy development is likely explained by the complex interaction of a range of factors: the existence of a previously established evidence-based culture among obstetricians; the movement of "networked" individuals immersed in that culture into key positions in the new government; the involvement of researchers in policy development; and the willingness of individuals and groups to lobby and advocate both for the development of policy and for the use of evidence in that policy. Discussion and Conclusions: The findings highlight the role played by researchers in developing evidence based policies and guidelines. It also points to the complexity of the relationship between knowledge production and the utilisation of research in policy. It suggests that while researchers may not be in control of factors such as political change, they are presented with windows of opportunity that may allow them to affect policy change. Their capacity to affect such change can be enhanced through collective action when researchers are organised through academic networks.

Hypertensive disorders of pregnancy (HDP), particularly pre-eclampsia and eclampsia, remain one of the leading causes of maternal mortality and are contributory in many foetal/newborn deaths. This editorial discusses a supplement of seven papers which provide the results of the first round of the CLIP (Community Level Interventions for Pre-eclampsia) Feasibility Studies. These studies report a number of enablers and barriers in each setting, which have informed the implementation of a cluster-randomized trial (cRCT) aimed at reducing pre-eclampsia-related, and all-cause, maternal and perinatal mortality and major morbidity using community-based identification and treatment of pre-eclampsia in selected geographies of Nigeria, Mozambique, Pakistan and India. This supplement unpacks the diverse community perspectives on determinants of maternal health, variant health worker knowledge and routine management of HDP, and viability of task sharing for preeclampsia identification and management in select settings. These studies demonstrate the need for strategies to improve health worker knowledge and routine management of HDP and consideration of expanding the role of community health workers to reach the most remote women and families with health education and access to health services. Fil: Kinney, Mary V.. No especifíca; Fil: Smith, Jeffrey Michael. Jhpiego; Estados Unidos Fil: Doherty, Tanya. South African Medical Research Council; Sudáfrica. University of the Western Cape; Sudáfrica Fil: Hermida, Jorge. University Research Company; Estados Unidos Fil: Daniels, Karen. South African Medical Research Council; Sudáfrica. University of the Western Cape; Sudáfrica Fil: Belizan, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; Argentina

This thesis concerns the reasons why some primary school headteachers in England include Food Education so prominently in their school’s pedagogical curriculum. School leaders are seen as the ‘architects’ of transforming the food culture within a school setting. The current inclusion of Food Education in the English National Curriculum focuses on teaching children about how food choices can have a positive impact on their own physical health and well-being. My study investigates if there are other reasons why a set of recognised leaders in Food Education include this learning focus in their school’s curriculum despite the fact that this is not an area for which they are held accountable. This qualitative research study is based on semi-structured interviews with ten primary school headteachers in England. The responses from the face-to-face semi-structured interviews with the headteachers are submitted to Reflective Thematic Analysis which leads to two contributions to the literature, summarised below. The theoretical framework takes a social constructionist approach, focusing on the interpretation of the school leaders’ views, experiences and practices of including Food Education into their school’s curriculum. My findings reveal that the headteachers who do include Food Education in their school’s pedagogical curriculum do not use it solely to support the healthy eating agenda. By shaping the school ethos and culture through the communication of their personal and professional values and vision, they are also able to extend the wider benefits of Food Education to positively influence other aspects of the school and the wider community. Their use of the ‘pedagogical curriculum’ as a stimulus has enabled them to enact what I call ‘pedagogical commensality’ which supports school connectedness and has the potential to have wide ranging benefits to both the children's academic and health outcomes and the wider community. Recommendations relate to government policy on incorporating learning about food in its broader context into the English National Curriculum. By including the social, cultural, political, environmental, aesthetic and sustainable benefits of food, schools could provide learning opportunities that extend beyond the narrow bio-pedagogical focus that Food Education currently occupies and could support key areas such as community cohesion, personal values development and inclusion. This has implications for the professional development of school leaders and the inclusion of Food Education curriculum in Initial Teacher Training programmes. This thesis claims new knowledge in relation to how Food Education can be used as an embodiment of the headteacher’s values-based leadership approach; and how ‘pedagogical commensality’ can be used as a tool to support the personal and social development of the children and the school community.