836 research outputs found

    The effect of photochemical ageing and initial precursor concentration on the composition and hygroscopic properties of β-caryophyllene secondary organic aerosol

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    The effect of photochemical ageing and initial precursor concentration on the composition and hygroscopic properties of secondary organic aerosol (SOA) formed during the chamber photo-oxidation of β-caryophyllene/NO<sub>x</sub> mixtures were investigated. Nucleation of β-caryophyllene SOA particles occurred almost immediately after oxidation was initiated and led to the formation of fresh SOA with a relatively simpler composition than has been reported for monoterpenes. The SOA yield values ranged from 9.5–26.7% and 30.4–44.5% using a differential mobility particle sizer (DMPS) and an aerosol mass spectrometer (AMS) mass based measurements, respectively. A total of 20 compounds were identified in the SOA by LC-MS/MS, with the most abundant compounds identified as β-caryophyllonic acid and β-caryophyllinic acid/β-nocaryophyllonic acid. The O:C and H:C elemental ratios of products identified in the condensed phase ranged from 0.20 to 1.00 and 1.00 to 2.00, with average values of 0.39 and 1.58, respectively. The increase in the O:C ratio was associated with a decrease in the saturation concentration of the identified compounds. The compounds identified in the lower initial concentration experiments were more oxidised compared to those that were found to be more abundant in the higher initial concentration experiments with average O:C ratios of 0.51 and 0.27, respectively. Photochemical ageing led to a more complex SOA composition with a larger contribution coming from lower molar mass, higher generation products, where both double bonds had been oxidised. This effect was more evident in the experiments conducted using the lower initial precursor concentration; a finding confirmed by the temporal behaviour of key organic mass fragment measured by an Aerosol Mass Spectrometer. Although the composition changed with both initial precursor concentration and ageing, this had no significant measurable effect on the hygroscopic properties of the SOA formed. The latter finding might have been influenced by the difference in pre-treatment of the semivolatile-containing particles prior to their measurements

    Subordinate Actors’ Institutional Maintenance in Response to Coercive Reforms

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    Institutional work research shows how actors purposively create, maintain, and disrupt institutions. Failed or unintended consequences of institutional maintenance remain relatively unexplored, for two reasons. First, the role of coercive disruption actors (e.g., a state) has not been fully explored. Second, existing literature takes scant account of power and disregards the resistance tactics of subordinate actors. Drawing on a longitudinal case study of a migrant workers’ union in China, we show how subordinate actors were first able to maintain institutional arrangements followed by a maintenance failure under the disruption work performed by the authoritarian state. This study extends the institutional maintenance literature in two ways. First, subordinate actors can sustain institutions insofar as they collectively deploy superficial deference and hidden forms of resistance. Second, maintenance work is vulnerable in the sense that it is contingent on the systems of domination and the level of pressure exerted by the disruption actors

    Confronting the digital:Doing ethnography in modern organizational settings

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    Digital technologies pervade modern life. As a result, organizational ethnographers must contend with informants interacting in face-to-face and digitally mediated encounters (e.g., through email, Facebook Messenger, and Skype). This overlap of informants’ digital and physical interactions challenges ethnographers’ ability to demonstrate authenticity and multivocality in their accounts of contemporary organizing. Drawing on recent theorizing about the nature of digital artifacts and two cases of ethnographic fieldwork, we argue that digital artifacts afford ethnographers different modes of being co-present with research participants: digital as archive and digital as process. We offer guidelines to researchers on how to deploy these modes of co-presence in order to improve authenticity and multivocality in ethnographic studies of modern organizations. We also explore the implications for methodological concerns such as ethics, analytical choice, and reflexivity

    The writing on the wall: the concealed communities of the East Yorkshire horselads

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    This paper examines the graffiti found within late nineteenth and early-twentieth century farm buildings in the Wolds of East Yorkshire. It suggests that the graffiti were created by a group of young men at the bottom of the social hierarchy - the horselads – and was one of the ways in which they constructed a distinctive sense of communal identity, at a particular stage in their lives. Whilst it tells us much about changing agricultural regimes and social structures, it also informs us about experiences and attitudes often hidden from official histories and biographies. In this way, the graffiti are argued to inform our understanding, not only of a concealed community, but also about their hidden histor

    Circadian control of mouse heart rate and blood pressure by the suprachiasmatic nuclei:behavioral effects are more significant than direct outputs

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    Diurnal variations in the incidence of events such as heart attack and stroke suggest a role for circadian rhythms in the etiology of cardiovascular disease. The aim of this study was to assess the influence of the suprachiasmatic nucleus (SCN) circadian clock on cardiovascular function. mice and WT. However, there was also a modest circadian rhythm of resting HR and BP that was independent of LA.If appropriate methods of analysis are used that take into account sleep and locomotor activity level, mice are a good model for understanding the contribution of circadian timing to cardiovascular function. Future studies of the influence of sleep and wakefulness on cardiovascular physiology may help to explain accumulating evidence linking disrupted sleep with cardiovascular disease in man

    THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE

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    Interdependence is a core concept in organization design, yet one that has remained consistently understudied. Current notions of interdependence remain rooted in seminal works, produced at a time when managers’ near-perfect understanding of the task at hand drove the organization design process. In this context, task interdependence was rightly assumed to be exogenously determined by characteristics of the work and the technology. We no longer live in that world, yet our view of interdependence has remained exceedingly task-centric and our treatment of interdependence overly deterministic. As organizations face increasingly unpredictable workstreams and workers co-design the organization alongside managers, our field requires a more comprehensive toolbox that incorporates aspects of agent-based interdependence. In this paper, we synthesize research in organization design, organizational behavior, and other related literatures to examine three types of interdependence that characterize organizations’ workflows: task, goal, and knowledge interdependence. We offer clear definitions for each construct, analyze how each arises endogenously in the design process, explore their interrelations, and pose questions to guide future research

    An Outside-Inside Evolution in Gender and Professional Work

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