133 research outputs found

    An open multi-physics framework for modelling wildland-urban interface fire evacuations

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    Fire evacuations at wildland-urban interfaces (WUI) pose a serious challenge to the emergency services, and are a global issue affecting thousands of communities around the world. This paper presents a multi-physics framework for the simulation of evacuation in WUI wildfire incidents, including three main modelling layers: wildfire, pedestrians, and traffic. Currently, these layers have been mostly modelled in isolation and there is no comprehensive model which accounts for their integration. The key features needed for system integration are identified, namely: consistent level of refinement of each layer (i.e. spatial and temporal scales) and their application (e.g. evacuation planning or emergency response), and complete data exchange. Timelines of WUI fire events are analysed using an approach similar to building fire engineering (available vs. required safe egress times for WUI fires, i.e. WASET/WRSET). The proposed framework allows for a paradigm shift from current wildfire risk assessment and mapping tools towards dynamic fire vulnerability mapping. This is the assessment of spatial and temporal vulnerabilities based on the wildfire threat evolution along with variables related to the infrastructure, population and network characteristics. This framework allows for the integration of the three main modelling layers affecting WUI fire evacuation and aims at improving the safety of WUI communities by minimising the consequences of wildfire evacuations

    Evaluation of camel milk for selected processing related parameters and comparisons with cow and buffalo milk

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    Cow and buffalo milk and camel milk were analyzed and compared for processing related parameters. The average heat stability of cow, buffalo and camel milk samples analyzed was 1807.4 seconds, 1574.6 seconds and 133.6 seconds respectively at 140 °C. Thus, the heat stability of camel milk was significantly lower than the cow milk and buffalo milk. The average rennet coagulation time (RCT) of cow, buffalo and camel milk was 310.6 seconds, 257.4 seconds and 604.2 seconds respectively. Thus, RCT of camel milk was significantly higher than the cow milk and buffalo milk. The camel, cow and buffalo milk samples showed negative alcohol stability. The rate of acidity was increased propositionally with time in camel milk with no curd formation and weaker body

    The cooperative behaviour of antimicrobial peptides in model membranes

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    A systematic analysis of the hypothesis of the antimicrobial peptides' (AMPs) cooperative action is performed by means of full atomistic molecular dynamics simulations accompanied by circular dichroism experiments. Several AMPs from the aurein family (2.5,2.6, 3.1), have a similar sequence in the first ten amino acids, are investigated in different environments including aqueous solution, trifluoroethanol (TFE), palmitoyloleoylphosphatidylethanolamine (POPE), and palmitoyloleoylphosphatidylglycerol (POPG) lipid bilayers. It is found that the cooperative effect is stronger in aqueous solution and weaker in TFE. Moreover, in the presence of membranes, the cooperative effect plays an important role in the peptide/lipid bilayer interaction. The action of AMPs is a competition of the hydrophobic interactions between the side chains of the peptides and the hydrophobic region of lipid molecules, as well as the intra peptide interaction. The aureins 2.5-COOH and 2.6-COOH form a hydrophobic aggregate to minimize the interaction between the hydrophobic group and the water. Once that the peptides reach the water/lipid interface the hydrophobic aggregate becomes smaller and the peptides start to penetrate into the membrane. In contrast, aurein 3.1-COOH forms only a transient aggregate which disintegrates once the peptides reached the membrane, and it shows no cooperativity in membrane penetratio

    The Materiality of Absence:Organizing and the case of the incomplete cathedral

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    This study explores the role of absences in making organizing possible. By engaging with Lefebvre’s spatial triad as the interconnections between conceived (planned), perceived (experienced through practice) and lived (felt and imagined) spaces, we challenge the so-called metaphysics of presence in organization studies. We draw on the insights offered by the project of construction of Siena Cathedral during the period 1259– 1357 and we examine how it provided a space for the actors involved to explore their different (civic, architectural and religious) intentions. We show that, as the contested conceived spaces of the cathedral were connected to architectural practices, religious powers and civic symbols, they revealed the impossibility for these intentions to be fully represented. It was this impossibility that provoked an ongoing search for solutions and guaranteed a combination of dynamism and persistence of both the material architecture of the cathedral and the project of construction. The case of Siena Cathedral therefore highlights the role of absence in producing organizing effects not because absence eventually takes form but because of the impossibility to fully represent it

    The social effects of entrepreneurship on society and some potential remedies: four provocations

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    A rapidly growing research stream examines the social effects of entrepreneurship on society. This research assesses the rise of entrepreneurship as a dominant theme in society and studies how entrepreneurship contributes to the production and acceptance of socio-economic inequality regimes, social problems, class and power struggles, and systemic inequities. In this article, scholars present new perspectives on an organizational sociology-inspired research agenda of entrepreneurial capitalism and detail the potential remedies to bound the unfettered expansion of a narrow conception of entrepreneurship. Taken together, the essays put forward four central provocations: 1) reform the study and pedagogy of entrepreneurship by bringing in the humanities; 2) examine entrepreneurship as a cultural phenomenon shaping society; 3) go beyond the dominant biases in entrepreneurship research and pedagogy; and 4) explore alternative models to entrepreneurial capitalism. More scholarly work scrutinizing the entrepreneurship–society nexus is urgently needed, and these essays provide generative arguments toward further developing this research agenda

    Research strategies for organizational history:a dialogue between historical theory and organization theory

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    If history matters for organization theory, then we need greater reflexivity regarding the epistemological problem of representing the past; otherwise, history might be seen as merely a repository of ready-made data. To facilitate this reflexivity, we set out three epistemological dualisms derived from historical theory to explain the relationship between history and organization theory: (1) in the dualism of explanation, historians are preoccupied with narrative construction, whereas organization theorists subordinate narrative to analysis; (2) in the dualism of evidence, historians use verifiable documentary sources, whereas organization theorists prefer constructed data; and (3) in the dualism of temporality, historians construct their own periodization, whereas organization theorists treat time as constant for chronology. These three dualisms underpin our explication of four alternative research strategies for organizational history: corporate history, consisting of a holistic, objectivist narrative of a corporate entity; analytically structured history, narrating theoretically conceptualized structures and events; serial history, using replicable techniques to analyze repeatable facts; and ethnographic history, reading documentary sources "against the grain." Ultimately, we argue that our epistemological dualisms will enable organization theorists to justify their theoretical stance in relation to a range of strategies in organizational history, including narratives constructed from documentary sources found in organizational archives. Copyright of the Academy of Management, all rights reserved

    Conceptualizing historical organization studies

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    © 2016 Academy of Management Review. The promise of a closer union between organizational and historical research has long been recognized. However, its potential remains unfulfilled: The authenticity of theory development expected by organization studies and the authenticity of historical veracity required by historical research place exceptional conceptual and empirical demands on researchers. We elaborate the idea of historical organization studies-organizational research that draws extensively on historical data, methods, and knowledge to promote historically informed theoretical narratives attentive to both disciplines. Building on prior research, we propose a typology of four differing conceptions of history in organizational research: History as evaluating, explicating, conceptualizing, and narrating. We identify five principles of historical organization studies-dual integrity, pluralistic understanding, representational truth, context sensitivity, and theoretical fluency-and illustrate our typology holistically from the perspective of institutional entrepreneurship. We explore practical avenues for a creative synthesis, drawing examples from social movement research and microhistory. Historically informed theoretical narratives whose validity derives from both historical veracity and conceptual rigor afford dual integrity that enhances scholarly legitimacy, enriching understanding of historical, contemporary, and future-directed social realities

    Respiration of Vorticella

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