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
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
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
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
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
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Performative Work: Bridging Performativity and Institutional Theory in the Responsible Investment Field
Callon’s performativity thesis has illuminated how economic theories and calculative devices shape markets, but has been challenged for its neglect of the organizational, institutional and political context. Our seven-year qualitative study of a large financial data company found that the company’s initial attempt to change the responsible investment field through a performative approach failed because of the constraints posed by field practices and organizational norms on the design of the calculative device. However, the company was subsequently able to put in place another form of performativity by attending to the normative and regulative associations of the device. We theorize this route to performativity by proposing the concept of performative work, which designates the necessary institutional work to enable translation and the subsequent adoption of the device. We conclude by considering the implications of performative work for the performativity and the institutional work literatures
Circadian control of mouse heart rate and blood pressure by the suprachiasmatic nuclei:behavioral effects are more significant than direct outputs
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
Managing depression in people with multimorbidity: a qualitative evaluation of an integrated collaborative care model
THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE
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
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