167 research outputs found
Entropy production from stochastic dynamics in discrete full phase space
The stochastic entropy generated during the evolution of a system interacting
with an environment may be separated into three components, but only two of
these have a non-negative mean. The third component of entropy production is
associated with the relaxation of the system probability distribution towards a
stationary state and with nonequilibrium constraints within the dynamics that
break detailed balance. It exists when at least some of the coordinates of the
system phase space change sign under time reversal, and when the stationary
state is asymmetric in these coordinates. We illustrate the various components
of entropy production, both in detail for particular trajectories and in the
mean, using simple systems defined on a discrete phase space of spatial and
velocity coordinates. These models capture features of the drift and diffusion
of a particle in a physical system, including the processes of injection and
removal and the effect of a temperature gradient. The examples demonstrate how
entropy production in stochastic thermodynamics depends on the detail that is
included in a model of the dynamics of a process. Entropy production from such
a perspective is a measure of the failure of such models to meet Loschmidt's
expectation of dynamic reversibility
Inhabiting infrastructure: exploring the interactional spaces of urban cycling
Contemporary cities are thick with infrastructure. In recognition of this fact a great deal of recent work within urban studies and urban geography has focused on transformations in the governance and ownership of infrastructural elements within cities. Less attention has been paid to the practices through which urban infrastructures are inhabited by urban dwellers. Yet in all sorts of ways infrastructures are realised through their use and inhabitation. This paper argues for the importance of attending to the ways that infrastructures are reinterpreted through use. Focusing on a case study of commuter cyclists in London, it explores the ways in which cyclists accommodate themselves to (and are in turn accommodated by) the infrastructural orderings of London’s streets. Confronted by the obduracy of a road infrastructure designed primarily for motorised traffic, cyclists show a diverse range of approaches to negotiating movement through the city on bikes. The paper describes how this negotiation can be understood in terms of the more or less skilful processes of navigation, rule following, rule making, and rule bending. This involves a polymorphous mix of practices, some common to driving, others to walking, and yet others unique to cycling. In conclusion, the paper suggests that transformations of infrastructures found within cities need to be understood as much through emergent changes between their elements, and that close attention to how infrastructures come to be inhabited offers productive avenues for thinking about ways to improve them
(Mobility) Fixing the Taiwanese bicycle industry: the production and economisation of cycling culture in pursuit of accumulation
There have been recent calls in mobilities literature for greater engagement with how mobility regimes are shaped and governed at different scales. In relation to cycling-related mobilities scholarship, there are very few accounts situating cycling within broader bio-political and political–economic processes. This paper seeks to address this absence, situating contemporary formations of cycling culture within processes of capital accumulation and economisation. The research is based upon a series of interviews with industry stakeholders, participant observations at cycle events and analysis of policy documents and news media in Taiwan from 2015–2017. We demonstrate that in the last 10–15 years there has been a drive to create cycling subjects in the Taiwanese cycle industry, mass events and through public bike sharing with the loosely strategised goal of projecting an image of a cycling culture that it is hoped will be advantageous to the domestic bicycle industry. We demonstrate how this emergent process of fixing works through economisation of social cycling practices, themselves reliant on processes of division, classification and subjectification. We also show how the cycling subjects and cultures thus formed constitute qualculative framings that facilitate ongoing commercial re-evaluation of Taiwanese Brand manufacturers by other actors within the industry
The impact of a minimal smoking cessation intervention for pregnant women and their partners on perinatal smoking behaviour in primary health care: A real-life controlled study
<p>Abstract</p> <p>Background</p> <p>There is a demand for strategies to promote smoking cessation in high-risk populations like smoking pregnant women and their partners. The objectives of this study were to investigate parental smoking behaviour during pregnancy after introduction of a prenatal, structured, multi-disciplinary smoking cessation programme in primary care, and to compare smoking behaviour among pregnant women in the city of Trondheim with Bergen and Norway.</p> <p>Methods</p> <p>Sequential birth cohorts were established to evaluate the intervention programme from September 2000 to December 2004 in primary care as a part of the Prevention of Allergy among Children in Trondheim study (PACT). The primary outcome variables were self reported smoking behaviour at inclusion and six weeks postnatal. Data from the Medical Birth Registry of Norway (MBR) were used to describe smoking cessation during pregnancy in Trondheim, Bergen and Norway 1999–2004.</p> <p>Results</p> <p>Maternal smoking prevalence at inclusion during pregnancy were 5% (CI 95% 4–6) in the intervention cohort compared to 7% (CI 95% 6–9), p = 0.03, in the control cohort. Of the pre-pregnancy maternal smokers 25% (CI 95% 20–31) and 32% (CI 95% 26–38), p = 0.17, were still smoking at inclusion in the intervention and control cohorts, respectively. Six weeks postnatal 72% (CI 95% 59–83) and 68% (CI 95% 57–77), p = 0.34 of the maternal smokers at inclusion still smoked. No significant difference in paternal smoking between the cohorts was found after the intervention period. Data from the MBR showed a significantly higher proportion of women who stopped smoking during pregnancy in Trondheim than in Bergen in 2003 and 2004, p = 0.03 and < 0.001, respectively.</p> <p>Conclusion</p> <p>No impact on parental smoking behaviour between the cohorts was observed after the smoking intervention programme. Of the women who stopped smoking during pregnancy most of them stopped smoking before the intervention. However, we observed a significantly higher quitting rate in Trondheim than in Bergen in 2003 and 2004 which may have been facilitated by the supplemental attention on smoking behaviour the PACT study initiated.</p
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'Instead of "closing down" at our ages… we’re thinking of exciting and challenging things to do': older people’s microadventures outdoors on (e-)bikes
This paper explores how people aged 50 and over, who were returning to cycling as part of an eight-week health and wellbeing trial, created their own cycling microadventures. Applying a stage model of the process of adventure to qualitative data generated from personal diaries and focus groups, we examine how older people anticipated and prepared for their microadventures, the challenges and discoveries they experienced, the benefits they gained and how electrically assisted ‘e-bikes’ can provide further opportunities for adventure. We conclude that cycles are a mode uniquely placed to facilitate microadventures and that e-bikes, in particular, offer further potential to enable older people to (re-)connect with place and other people. But, while this type of activity can provide benefits in terms of health and wellbeing, we argue that more supportive physical and social infrastructure is required to provide opportunities for more people to undertake microadventures close to their homes
Impact of the Spanish Smoking Law on Exposure to Second-Hand Smoke and Respiratory Health in Hospitality Workers: A Cohort Study
A smoke-free law came into effect in Spain on 1st January 2006, affecting all enclosed workplaces except hospitality venues, whose proprietors can choose among totally a smoke-free policy, a partial restriction with designated smoking areas, or no restriction on smoking on the premises. We aimed to evaluate the impact of the law among hospitality workers by assessing second-hand smoke (SHS) exposure and the frequency of respiratory symptoms before and one year after the ban
Contemporary contestations over working time: time for health to weigh in
Non-communicable disease (NCD) incidence and prevalence is of central concern to most nations, along with international agencies such as the UN, OECD, IMF and World Bank. As a result, the search has begun for ‘causes of the cause’ behind health risks and behaviours responsible for the major NCDs. As part of this effort, researchers are turning their attention to charting the temporal nature of societal changes that might be associated with the rapid rise in NCDs. From this, the experience of time and its allocation are increasingly understood to be key individual and societal resources for health (7–9). The interdisciplinary study outlined in this paper will produce a systematic analysis of the behavioural health dimensions, or ‘health time economies’ (quantity and quality of time necessary for the practice of health behaviours), that have accompanied labour market transitions of the last 30 years - the period in which so many NCDs have risen sharply
Commoning mobility:Towards a new politics of mobility transitions
Scholars have argued that transitions to more sustainable and just mobilities require
moving beyond technocentrism to rethink the very meaning of mobility in cities,
communities, and societies. This paper demonstrates that such rethinking is inherently
political. In particular, we focus on recent theorisations of commoning practices
that have gained traction in geographic literatures. Drawing on our global
comparative research of low‐carbon mobility transitions, we argue that critical
mobilities scholars can rethink and expand the understanding of mobility through
engagement with commons–enclosure thinking. We present a new concept, “commoning
mobility,” a theorisation that both envisions and shapes practices that
develop fairer and greener mobilities and more inclusive, collaboratively governed
societies. Our analysis introduces three “logics” of mobility transition projects. First,
the paper discusses how a logic of scarcity has been a driver for mobility planning
as the scarcity of oil, finance, space, and time are invoked across the world as stimuli
for aspiring to greener, “smarter,” and cheaper mobilities. The paper then identifies
two responses to the logic of scarcity: the logics of austerity and the logics of commoning.
Austere mobilities are examined to problematise the distribution of responsibility
for emissions and ensuing injustices and exclusion in low‐carbon transitions.
The logics of commoning shows a potential to reassess mobility not only as an individual
freedom but also as a collective good, paving the way for fairer mobility transitions
and a collaborative tackling of sustainable mobility challenges.info:eu-repo/semantics/publishedVersio
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