327 research outputs found
Future making and visual artefacts : an ethnographic study of a design project
Current research on strategizing and organizing has explored how practitioners make sense of an uncertain future, but provides limited explanations of how they actually make a realizable course of action for the future. A focus on making rather than sensemaking brings into view the visual artefacts that practitioners use in giving form to what is ânot yetâ â drawings, models and sketches. We explore how visual artefacts are used in making a realizable course of action, by analysing ethnographic data from an architectural studio designing a development strategy for their client. We document how visual artefacts become enrolled in practices of imagining, testing, stabilizing and reifying, through which abstract imaginings of the future are turned into a realizable course of action. We then elaborate on higher-order findings that are generalizable to a wide range of organizational settings, and discuss their implications for future research in strategizing and organizing. This paper contributes in two ways: first, it offers future making as an alternative perspective on how practitioners orient themselves towards the future (different from current perspectives such as foreseeing, future perfect thinking and wayfinding). Second, it advances our understanding of visual artefacts and their performativity in the making of organizational futures
Mathematical model of blood and interstitial flow and lymph production in the liver.
We present a mathematical model of blood and interstitial flow in the liver. The liver is treated as a lattice of hexagonal \u2018classic\u2019 lobules, which are assumed to be long enough that end effects may be neglected and a
two-dimensional problem considered. Since sinusoids and lymphatic vessels are numerous and small compared to the lobule, we use a homogenized approach, describing the sinusoidal and interstitial spaces as porous media. We model plasma filtration from sinusoids to the interstitium, lymph uptake by lymphatic ducts, and lymph outflow from the liver
surface. Our results show that the effect of the liver surface only penetrates a depth of a few lobules\u2019 thickness into the tissue. Thus, we separately consider a single lobule lying sufficiently far from all external boundaries that we may regard it as being in an infinite lattice, and also a model of the region near the liver surface. The model predicts that slightly more lymph is produced by interstitial fluid flowing through the liver surface than that taken up by the lymphatic vessels in the liver and that the on-peritonealized region of the surface of the liver results in the total lymph production (uptake by lymphatics plus fluid crossing surface) being about 5 % more than if the entire surface were covered by the Glisson\u2013peritoneal membrane. Estimates of lymph outflow through the surface of the liver are in good agreement with experimental data. We also study the effect of non-physiological values of the controlling parameters, particularly focusing
on the conditions of portal hypertension and ascites. To our knowledge, this is the first attempt to model lymph production in the liver. The model provides clinically relevant information about lymph outflow pathways and predicts the systemic response to pathological variations
Dispelling urban myths about default uncertainty factors in chemical risk assessment - Sufficient protection against mixture effects?
© 2013 Martin et al.; licensee BioMed Central LtdThis article has been made available through the Brunel Open Access Publishing Fund.Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) of uncertainty factors can only be considered in relation to a defined level of protection. A protection equivalent to an effect magnitude of 0.001-0.0001% over background incidence is generally considered acceptable. However, it is impossible to say whether this level of protection is in fact realised with the tolerable doses that are derived by employing uncertainty factors. Accordingly, it is difficult to assess whether uncertainty factors overestimate or underestimate the sensitivity differences in human populations. It is also often not appreciated that the outcome of probabilistic approaches to the multiplication of sub-factors is dependent on the choice of probability distributions. Therefore, the idea that default uncertainty factors are overly conservative worst-case scenarios which can account both for the lack of statistical power in animal experiments and protect against potential mixture effects is ill-founded. We contend that precautionary regulation should provide an incentive to generate better data and recommend adopting a pragmatic, but scientifically better founded approach to mixture risk assessment. © 2013 Martin et al.; licensee BioMed Central Ltd.Oak Foundatio
Failure or success? Defensive strategies and piecemeal change among racial inequalities in the Brazilian banking sector
We analyze how Brazilian Black Movement organizations and banks deployed different mechanisms like cooperation, cooptation, and confrontation that generated affirmative action initiatives in the banking sector at the beginning of this century. Black movement organizations triggered an institutional change by connecting fields and exploring a constellation of strategies. However, Brazilian banks adopted defensive strategies aiming to accommodate their interests. We find that only piecemeal change occurred, as the fieldâs structures â resource distribution and power â remained unscratched. We conclude by noting how the success of social movement strategies can depend upon the framing and sense-giving work that social movements conduct in their continuous jockeying activity toward incumbents
From Interactions to Institutions: Microprocesses of Framing and Mechanisms for the Structuring of Institutional Fields
Despite the centrality of meaning to institutionalization, little attention has been paid to how meanings evolve and amplify to become institutionalized cultural conventions. We develop an interactional framing perspective to explain the microprocesses and mechanisms by which this occurs. We identify three amplification processes and three ways frames stack up or laminate that become the building blocks for diffusion and institutionalization of meanings within organizations and fields. Although we focus on âbottom-upâ dynamics, we argue that framing occurs in a politicized social context and is inherently bidirectional, in line with structuration, because microlevel interactions instantiate macrostructures. We consider how our approach complements other theories of meaning making, its utility for informing related theoretical streams, and its implications for organizing at the meso and macro levels
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Sources of stakeholder salience in the responsible investment movement: why do investors sign the Principles for Responsible Investment?
Since its inception in 2006, the United Nations-backed Principles for Responsible Investment (PRI) have grown to over 1300 signatories representing over $45 trillion. This growth is not slowing down. In this paper, we argue that there is a set of attributes which make the PRI salient as a stakeholder and its claim to sign the six PRI important to institutional investors. We use Mitchell et al.âs (Acad Manag Rev 22:853â886, 1997) theoretical framework of stakeholder salience, as extended by Gifford (J Bus Eth 92:79â97, 2010). We use as evidence confidential data from the annual survey of signatories carried out by the PRI in a 5-year period between 2007 and 2011. The findings highlight pragmatic and organizational legitimacy, normative and utilitarian power, and management values as the attributes that contribute most to the salience of the PRI as a stakeholder
Towards an articulation of the material and visual turn in organization studies
International audienceContemporary organizations increasingly rely on images, logos, videos, building materials, graphic andproduct design, and a range of other material and visual artifacts to compete, communicate, form identityand organize their activities. This Special Issue focuses on materiality and visuality in the course of objectifyingand reacting to novel ideas, and, more broadly, contributes to organizational theory by articulating theemergent contours of a material and visual turn in the study of organizations. In this Introduction, weprovide an overview of research on materiality and visuality. Drawing on the articles in the special issue, wefurther explore the affordances and limits of the material and visual dimensions of organizing in relation tonovelty. We conclude by pointing out theoretical avenues for advancing multimodal research, and discusssome of the ethical, pragmatic and identity-related challenges that a material and visual turn could pose fororganizational research
Deterministic Chaos and Fractal Complexity in the Dynamics of Cardiovascular Behavior: Perspectives on a New Frontier
Physiological systems such as the cardiovascular system are capable of five kinds of behavior: equilibrium, periodicity, quasi-periodicity, deterministic chaos and random behavior. Systems adopt one or more these behaviors depending on the function they have evolved to perform. The emerging mathematical concepts of fractal mathematics and chaos theory are extending our ability to study physiological behavior. Fractal geometry is observed in the physical structure of pathways, networks and macroscopic structures such the vasculature and the His-Purkinje network of the heart. Fractal structure is also observed in processes in time, such as heart rate variability. Chaos theory describes the underlying dynamics of the system, and chaotic behavior is also observed at many levels, from effector molecules in the cell to heart function and blood pressure. This review discusses the role of fractal structure and chaos in the cardiovascular system at the level of the heart and blood vessels, and at the cellular level. Key functional consequences of these phenomena are highlighted, and a perspective provided on the possible evolutionary origins of chaotic behavior and fractal structure. The discussion is non-mathematical with an emphasis on the key underlying concepts
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