Exploring the role of managers in the development of a safety culture in seven French healthcare facilities: a qualitative study.

BACKGROUND: Numerous studies have been conducted over the past 15 years to assess safety culture within healthcare facilities; in general, these studies have shown the pivotal role that managers play in its development. However, little is known about what healthcare managers actually do to support this development, and how caregivers and managers represent managers'role. Thus the objectives of this study were to explore: i) caregivers and managers' perceptions and representations of safety, ii) the role of managers in the development of safety culture as perceived by themselves and by caregivers, iii) managers' activities related to the development of safety culture. METHODS: An exploratory, multicentre, qualitative study was conducted from May 2014 to March 2015 in seven healthcare facilities in France. Semi-structured interviews were conducted with managers (frontline, middle and top level) and caregivers (doctors, nurses and nurse assistants) and on-site observations of two managers were carried out in all facilities. A thematic analysis of semi-structured interviews was performed. Observed activities were categorised using Luthans' typology of managerial activities. RESULTS: Participants in semi-structured interviews (44 managers and 21 caregivers) expressed positive perceptions of the level of safety in their facility. Support from frontline management was particularly appreciated, while support from top managers was identified as an area for improvement. Six main categories of safety-related activities were both observed among managers and regularly expressed by participants. However, caregivers' expectations of their managers and managerial perceptions of these expectations only partially overlapped. CONCLUSIONS: The present study highlights current categories of managerial activities that foster safety culture, and points out an important gap between caregivers' expectations of their managers, and managerial perceptions of these expectations. The findings underline the need to allow more time for managers and caregivers to talk about safety issues. The results could be used to develop training programs to help healthcare managers to understand their role in the development of safety culture.

Going with the Flow: Multiscale Insights into the Composite Nature of Water Transport in Roots.

As water often limits crop production, a more complete understanding of plant water capture and transport is necessary. Here, we developed MECHA, a mathematical model that computes the flow of water across the root at the scale of walls, membranes, and plasmodesmata of individual cells, and used it to test hypotheses related to root water transport in maize (Zea mays). The model uses detailed root anatomical descriptions and a minimal set of experimental cell properties, including the conductivity of plasma membranes, cell walls, and plasmodesmata, which yield quantitative and scale-consistent estimations of water pathways and root radial hydraulic conductivity (k r). MECHA revealed that the mainstream hydraulic theories derived independently at the cell and root segment scales are compatible only if osmotic potentials within the apoplastic domains are uniform. The results suggested that the convection-diffusion of apoplastic solutes explained most of the offset between estimated k r in pressure clamp and osmotic experiments, while the contribution of water-filled intercellular spaces was limited. Furthermore, sensitivity analyses quantified the relative impact of cortex and endodermis cell conductivity of plasma membranes on root k r and suggested that only the latter contributed substantially to k r due to the composite nature of water flow across roots. The explicit root hydraulic anatomy framework brings insights into contradictory interpretations of experiments from the literature and suggests experiments to efficiently address questions pertaining to root water relations. Its scale consistency opens avenues for cross-scale communication in the world of root hydraulics.

Spring barley shows dynamic compensatory root and shoot growth responses when exposed to localised soil compaction and fertilisation.

The impact of heterogeneous soil compaction in combination with nutrient availability on root system architecture and root growth dynamics has scarcely been investigated. We quantified changes of barley (Hordeum vulgare L.) root and shoot growth during the first 3 weeks of growth in a controlled-environment chamber. Vertically divided split-root rhizotrons were filled either uniformly with loose or compacted peat, or heterogeneously with loose peat in one compartment and compacted peat in the other. We investigated the following questions. (a) Can growth processes affected by soil compaction be mimicked in our system? (b) Do plants show compensatory growth effects when exposed to heterogeneous soil compaction? (c) Does localised fertiliser application affect root systems' responses to compaction? We observed compensatory effects regarding root system architecture and root growth dynamics due to vertically heterogeneous soil compaction. Roots grew deeper and lateral roots emerged earlier in the loose compartment of the split-root treatment compared with uniform treatments. When fertiliser was applied only via the compacted compartment in the split-root treatment, more lateral roots were initiated in the compacted compartment and lateral root formation started a few days earlier than in the uniform treatments. Consequently, the first days after exposure to heterogeneous soil conditions are critical for the analysis of underlying physiological responses.

Disentangling who is who during rhizosphere acidification in root interactions: combining fluorescence with optode techniques.

Plant-soil interactions can strongly influence root growth in plants. There is now increasing evidence that root-root interactions can also influence root growth, affecting architecture and root traits such as lateral root formation. Both when species grow alone or in interaction with others, root systems are in turn affected by as well as affect rhizosphere pH. Changes in soil pH have knock-on effects on nutrient availability. A limitation until recently has been the inability to assign species identity to different roots in soil. Combining the planar optode technique with fluorescent plants enables us to distinguish between plant species grown in natural soil and in parallel study pH dynamics in a non-invasive way at the same region of interest (ROI). We measured pH in the rhizosphere of maize and bean in rhizotrons in a climate chamber, with ROIs on roots in proximity to the roots of the other species as well as not-close to the other species. We found clear dynamic changes of pH over time and differences between the two species in rhizosphere acidification. Interestingly, when roots of the two species were interacting, the degree of acidification or alkalization compared to bulk soil was less strong then when roots were not growing in the vicinity of the other species. This cutting-edge approach can help provide a better understanding of plant-plant and plant-soil interactions.

Root-root interactions: extending our perspective to be more inclusive of the range of theories in ecology and agriculture using in-vivo analyses.

BACKGROUND: There is a large body of literature on competitive interactions among plants, but many studies have only focused on above-ground interactions and little is known about root-root dynamics between interacting plants. The perspective on possible mechanisms that explain the outcome of root-root interactions has recently been extended to include non-resource-driven mechanisms (as well as resource-driven mechanisms) of root competition and positive interactions such as facilitation. These approaches have often suffered from being static, partly due to the lack of appropriate methodologies for in-situ non-destructive root characterization. SCOPE: Recent studies show that interactive effects of plant neighbourhood interactions follow non-linear and non-additive paths that are hard to explain. Common outcomes such as accumulation of roots mainly in the topsoil cannot be explained solely by competition theory but require a more inclusive theoretical, as well as an improved methodological framework. This will include the question of whether we can apply the same conceptual framework to crop versus natural species. CONCLUSIONS: The development of non-invasive methods to dynamically study root-root interactions in vivo will provide the necessary tools to study a more inclusive conceptual framework for root-root interactions. By following the dynamics of root-root interactions through time in a whole range of scenarios and systems, using a wide variety of non-invasive methods, (such as fluorescent protein which now allows us to separately identify the roots of several individuals within soil), we will be much better equipped to answer some of the key questions in root physiology, ecology and agronomy.

GROWSCREEN-Rhizo is a novel phenotyping robot enabling simultaneous measurements of root and shoot growth for plants grown in soil-filled rhizotrons.

Root systems play an essential role in ensuring plant productivity. Experiments conducted in controlled environments and simulation models suggest that root geometry and responses of root architecture to environmental factors should be studied as a priority. However, compared with aboveground plant organs, roots are not easily accessible by non-invasive analyses and field research is still based almost completely on manual, destructive methods. Contributing to reducing the gap between laboratory and field experiments, we present a novel phenotyping system (GROWSCREEN-Rhizo), which is capable of automatically imaging roots and shoots of plants grown in soil-filled rhizotrons (up to a volume of ~18L) with a throughput of 60 rhizotrons per hour. Analysis of plants grown in this setup is restricted to a certain plant size (up to a shoot height of 80cm and root-system depth of 90cm). We performed validation experiments using six different species and for barley and maize, we studied the effect of moderate soil compaction, which is a relevant factor in the field. First, we found that the portion of root systems that is visible through the rhizotrons' transparent plate is representative of the total root system. The percentage of visible roots decreases with increasing average root diameter of the plant species studied and depends, to some extent, on environmental conditions. Second, we could measure relatively minor changes in root-system architecture induced by a moderate increase in soil compaction. Taken together, these findings demonstrate the good potential of this methodology to characterise root geometry and temporal growth responses with relatively high spatial accuracy and resolution for both monocotyledonous and dicotyledonous species. Our prototype will allow the design of high-throughput screening methodologies simulating environmental scenarios that are relevant in the field and will support breeding efforts towards improved resource use efficiency and stability of crop yields.

The use of green fluorescent protein as a tool to identify roots in mixed plant stands.

Roots take up most of the resources required by a plant, but a lack of efficient research tools hinders our understanding of the function and relevance of the root system. This is especially evident when the research focus is not on a single plant, but on multiple plants that share the same soil resources. None of the available methods allow for simple, inexpensive, non-destructive, and objective assignment of observed roots in a mixture of plants to a target plant. Here, we demonstrate that transgenic plants expressing the green fluorescent protein (GFP), combined with the well established minirhizotron technique, is a route to overcoming this limitation. We planted transgenic maize (Zea mays L.) in combination with either its corresponding wild type, Italian ryegrass (Lolium multiflorum Lam.), or soybean (Glycine max (L.) Merr.). Identification of fluorescent roots allows the relative distribution of roots of each plant type and their interaction and interference with each other to be observed. The selected plants are suitable for model experiments to unravel fundamental belowground ecological processes. Because genetic transformation of plants is an established technique that can be applied to a large set of plant species, this method will be of interest to a broad range of research areas.