525 resultados para Bicycle commuting
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Objectives: To explore the associations of working hours ( paid, domestic, commuting, and total) with sickness absence, and to examine whether these associations vary according to the level of employee control over daily working hours.
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This article explores how the design and layout of the urban environment can have significant social impacts on working class communities whose access to employment and other necessary services depends largely on public transport and safe walk-able streets. It does so by considering a case study of Belfast. Although Belfast has a distinctive recent history as the site of political violence and territorial division, it also has a spatial configuration that emerged out of a modernising roads and redevelopment programme in the 1960s and 1970s. However, an understanding of contemporary Belfast, particularly its urban structure and form, requires n analysis of how the social impacts of such ubiquitous regional and urban planning practices were not addressed. The article argues that a culture of ‘politically safe’ bureaucratic inaction developed during the ‘war years’ has been sustained in the ‘new democracy’. In turn, this has had significant consequences for the functioning of the city. Major areas of derelict land around the city core together with the impediments created by regional road infrastructure have combined to create a doughnut city that, on the one hand, facilitates a commuting middle class, while on the other, discriminates against the poorest inner city communities. The article goes on to examine how an activist urban design group, known as the Forum for Alternative Belfast, has responded to these challenges. It focuses particularly on action-research undertaken during its 2010 Summer School which aimed to address issues of disconnection in inner North Belfast that affect some of the most territorialised and deprived communities in the city.
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Chan and Shapiro showed that each (non-trivial) translation operator acting on the Fréchet space of entire functions endowed with the topology of locally uniform convergence supports a universal function of exponential type zero. We show the existence of d-universal functions of exponential type zero for arbitrary finite tuples of pairwise distinct translation operators. We also show that every separable infinite-dimensional Fréchet space supports an arbitrarily large finite and commuting disjoint mixing collection of operators. When this space is a Banach space, it supports an arbitrarily large finite disjoint mixing collection of C0-semigroups. We also provide an easy proof of the result of Salas that every infinite-dimensional Banach space supports arbitrarily large tuples of dual d-hypercyclic operators, and construct an example of a mixing Hilbert space operator T so that (T,T2) is not d-mixing.
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A tuple $(T_1,\dots,T_n)$ of continuous linear operators on a topological vector space $X$ is called hypercyclic if there is $x\in X$ such that the the orbit of $x$ under the action of the semigroup generated by $T_1,\dots,T_n$ is dense in $X$. This concept was introduced by N.~Feldman, who have raised 7 questions on hypercyclic tuples. We answer those 4 of them, which can be dealt with on the level of operators on finite dimensional spaces. In
particular, we prove that the minimal cardinality of a hypercyclic tuple of operators on $\C^n$ (respectively, on $\R^n$) is $n+1$ (respectively, $\frac n2+\frac{5+(-1)^n}{4}$), that there are non-diagonalizable tuples of operators on $\R^2$ which possess an orbit being neither dense nor nowhere dense and construct a hypercyclic 6-tuple of operators on $\C^3$ such that every operator commuting with each member of the tuple is non-cyclic.
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We analyze the nature of the statistics of the work done on or by a quantum many-body system brought out of equilibrium. We show that, for the sudden quench and for an initial state that commutes with the initial Hamiltonian, it is possible to retrieve the whole nonequilibrium thermodynamics via single projective measurements of observables. We highlight, in a physically clear way, the qualitative implications for the statistics of work coming from considering processes described by operators that either commute or do not commute with the unperturbed Hamiltonian of a given system. We consider a quantum many-body system and derive an expression that allows us to give a physical interpretation, for a thermal initial state, to all of the cumulants of the work in the case of quenched operators commuting with the unperturbed Hamiltonian. In the commuting case, the observables that we need to measure have an intuitive physical meaning. Conversely, in the noncommuting case, we show that, although it is possible to operate fully within the single-measurement framework irrespectively of the size of the quench, some difficulties are faced in providing a clear-cut physical interpretation to the cumulants. This circumstance makes the study of the physics of the system nontrivial and highlights the nonintuitive phenomenology of the emergence of thermodynamics from the fully quantum microscopic description. We illustrate our ideas with the example of the Ising model in a transverse field showing the interesting behavior of the high-order statistical moments of the work distribution for a generic thermal state and linking them to the critical nature of the model itself.
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Background: Accurate assessment tools are required for the surveillance of physical activity (PA) levels and the assessment of the effect of interventions. In addition, increasing awareness of PA is often used as the first step in pragmatic behavioural interventions, as discrepancies between the amount of activity an individual perceives they do and the amount actually undertaken may act as a barrier to change. Previous research has demonstrated differences in the amount of activity individuals report doing, compared to their level of physical activity when measured with an accelerometer. Understanding the characteristics of those whose PA level is ranked differently when measured with either self-report or accelerometry is important as it may inform the choice of instrument for future research. The aim of this project was to determine which individual characteristics are associated with differences between self-reported and accelerometer measured physical activity.
Methods: Participant data from the 2009 wave of the Commuting and Health in Cambridge study were used. Quartiles of self-reported and accelerometer measured PA were derived by ranking each measure from lowest to highest. These quartiles were compared to determine whether individuals’ physical activity was ranked higher by either method. Multinomial logistic regression models were used to investigate the individual characteristics associated with different categories of mismatch.
Results: Data from 486 participants (70% female) were included in the analysis. In adjusted analyses, the physical activity of overweight or obese individuals was significantly more likely to be ranked higher by self-report than by accelerometer than that of normal-weight individuals (OR = 2.07, 95%CI = 1.28–3.34), particularly among women (OR = 3.97, 95%CI = 2.11–7.47).
Conclusions: There was a greater likelihood of mismatch between self-reported and accelerometer measured physical activity levels in overweight or obese adults. Future studies in overweight or obese adults should consider employing both methods of measurement.
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Background
Chronic kidney disease is now regarded as a risk factor for cardiovascular disease. The impact of occupational or non-occupational physical activity (PA) on moderate decreases of renal function is uncertain.
ObjectivesWe aimed to identify the potential association of PA (occupational and leisure-time) on early decline of estimated glomerular filtration rate (eGFR) and to determine the potential mediating effect of PA on the relationship between eGFR and heart disease.
MethodsFrom the PRIME study analyses were conducted in 1058 employed men. Energy expended during leisure, work and commuting was calculated. Linear regression analyses were used to determine the link between types of PA and moderate decrements of eGFR determined with the KDIGO guideline at the baseline assessment. Cox proportional hazards analyses were used to explore the potential effect of PA on the relationship between eGFR and heart disease, ascertained during follow-up over 10 years.
ResultsFor these employed men, and after adjustment for known confounders of GFR change, more time spent sitting at work was associated with increased risk of moderate decline in kidney function, while carrying objects or being active at work was associated with decreased risk. In contrast, no significant link with leisure PA was apparent. No potential mediating effect of occupational PA was found for the relationship between eGFR and coronary heart disease.
ConclusionOccupational PA (potential modifiable factors) could provide a dual role on early impairment of renal function, without influence on the relationship between early decrease of e-GFR and CHD risk.
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We express various sets of quantum correlations studied in the theoretical physics literature in terms of different tensor products of operator systems of discrete groups. We thus recover earlier results of Tsirelson and formulate a new approach for the study of quantum correlations. To do this we formulate a general framework for the study of operator systems arising from discrete groups. We study in detail the operator system of the free group Fn on n generators, as well as the operator systems of the free products of finitely many copies of the two-element group Z2. We examine various tensor products of group operator systems, including the minimal, the maximal, and the commuting tensor products. We introduce a new tensor product in the category of operator systems and formulate necessary and sufficient conditions for its equality to the commuting tensor product in the case of group operator systems.
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They’re cheap. They’re in every settlement of significance in Britain, Ireland and elsewhere. We all use them but perhaps do not always admit to it. Especially, if we are architects.
Over the past decades Aldi/Lidl low cost supermarkets have escaped from middle Europe to take over large tracts of the English speaking world remaking them according to a formula of mass-produced sheds, buff-coloured cobble-lock car parks, logos in primary colours, bare-shelves and eclectic special offers. Response within architectural discourse to this phenomenon has been largely one of indifference and such places remain, perhaps reiterating Pevsner’s controversial insights into the bicycle shed, on the peripheries of what we might term architecture. This paper seeks to explore the spatial complexities of the discount supermarket and in doing so open up a discussion on the architecture of cheapness. As a road-map, it takes former managing director Dieter Brandes’ treatise on the Aldi formula, Bare Essentials: the Aldi Way to Retailing, and investigates the strategies through which economic exigencies manifest themselves in a series of spatial tactics which involve building. Central to this is the idea of architecture as system rather than form and, in Aldi/Lidl’s case, the result of a spatial network of flows. To understand the architecture of the supermarket, then, it is necessary to measure the times and spaces of supply across the scales of intersection between global and local.
Evaluating the energy, economy and precision of such systems challenges the liminal position of the commercial, the placeless and especially the cheap within architectural discourse. As is well known, architectures of mass-production and prefabrication and their origins exercised modernist thinkers such as Sigfried Giedion and Walter Gropius in the early twentieth century and has undergone a resurgence in recent times. Meanwhile, the mapping of the hitherto overlooked forms and iconography of commerce in Learning from Las Vegas (1971) was extended by Rem Koolhaas et al into an investigation of the technologies, systems and precedents of retail in the Harvard Design School Guide to Shopping, thirty years later in 2001. While obviously always a criteria for building, to find writings on architecture which explicitly celebrate cheapness as a design virtue or, indeed, even iterate the word cheap is more difficult. Walter Gropius’ essay ‘How can we build cheaper, better, more attractive houses?’ (1927), however, situates the cheap within the discussions – articulated, amongst others, by Karl Teige and Bruno Taut – surrounding the minimal dwelling and the moral benefits of absence of the 1920s and 30s.
In our contemporary age of heightened consumption, it is perhaps fitting that an architecture of bare essentials is defined in retail rather than in housing, a commercial existenzminimum where the Miesian paradox of ‘less is more’ is resold as a paradigm of ‘more for less’ in the ubiquitous yet overlooked architectures of the discount supermarket.
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Physical inactivity is the fourth leading risk factor for global mortality, with most of these deaths occurring in low and middle-income countries (LMICs) like India. Research from developed countries has consistently demonstrated associations between built environment features and physical activity levels of populations. The development of culturally sensitive and reliable measures of the built environment is a necessary first step for accurate analysis of environmental correlates of physical activity in LMICs. This study systematically adapted the Neighborhood Environment Walkability Scale (NEWS) for India and evaluated aspects of test-retest reliability of the adapted version among Indian adults. Cultural adaptation of the NEWS was conducted by Indian and international experts. Semi-structured interviews were conducted with local residents and key informants in the city of Chennai, India. At baseline, participants (N = 370; female = 47.2%) from Chennai completed the adapted NEWS-India surveys on perceived residential density, land use mix-diversity, land use mix-access, street connectivity, infrastructure and safety for walking and cycling, aesthetics, traffic safety, and safety from crime. NEWS-India was administered for a second time to consenting participants (N = 62; female = 53.2%) with a gap of 2–3 weeks between successive administrations. Qualitative findings demonstrated that built environment barriers and constraints to active commuting and physical activity behaviors intersected with social ecological systems. The adapted NEWS subscales had moderate to high test-retest reliability (ICC range 0.48–0.99). The NEWS-India demonstrated acceptable measurement properties among Indian adults and may be a useful tool for evaluation of built environment attributes in India. Further adaptation and evaluation in rural and suburban settings in India is essential to create a version that could be used throughout India.
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O benzeno foi o primeiro poluente atmosférico carcinogénico a ser regulamentado a nível europeu. Vários trabalhos têm sido publicados demonstrando a relação deste poluente com diversos tipos de neoplasias nomeadamente decorrentes de exposições a nível ocupacional. Porém, o estudo deste poluente para concentrações atmosféricas em ambientes exteriores ainda é pouco conhecido e está em clara evolução. Neste sentido, este trabalho pretende ser um contributo para o conhecimento da relação entre o benzeno atmosférico e a incidência de patologias que afectam os tecidos linfáticos e órgãos hematopoiéticos nomeadamente linfomas de Hodgkin, linfomas de não-Hodgkin e leucemias na população residente na Área Metropolitana do Porto. Dado a quase ausência de dados de monitorização das concentrações de benzeno atmosférico actualmente em Portugal, estas foram estimadas com base na definição de uma relação entre o benzeno e o monóxido de carbono. O conhecimento das concentrações em todo o domínio de estudo baseou-se na análise dos dados da Rede Automática de Monitorização da Qualidade do Ar porém, de modo a aumentar o detalhe espacial e temporal recorreu-se à modelação atmosférica aplicando o modelo TAPM. Para perceber a evolução temporal das concentrações, a modelação foi efectuada para os anos de 1991, 2001 e 2006 com base no ano meteorológico de 2006 e emissões para os respectivos anos ao nível da freguesia. O modelo foi previamente validado de acordo com uma metodologia proposta para este tipo de modelos. Contudo, mais do que perceber qual a variação da qualidade do ar a nível exterior, é importante conhecer o impacte de fontes interiores e o seu efeito na população. Assim, desenvolveu-se um modelo de exposição e dose que permitem conhecer os valores médios populacionais. A modelação da exposição populacional é efectuada com base nos perfis de actividade-tempo, nos movimentos pendulares inter-concelhos e nas concentrações de benzeno em ambientes exteriores e interiores. Na modelação da dose é ainda possível variações por sexo e idade. Por outro lado, para o estudo das patologias em análise efectuou-se uma análise epidemiológica espacial nomeadamente no que respeita à elaboração de mapas de incidência padronizados pela idade, e estudo da associação com a exposição ao benzeno atmosférico. Os resultados indicam associação entre o benzeno e as doenças em estudo. Esta evidência é mais notória quando a análise é realizada junto às principais fontes de emissão deste poluente, vias de tráfego e postos de abastecimento de combustível. Porém, a ausência de informação limita o estudo não permitindo o controlo de potenciais variáveis de confundimento como a exposição ao fumo do tabaco. A metodologia permite efectuar uma gestão integrada da qualidade do ar exterior e interior, funcionando como uma ferramenta do apoio à decisão para elaboração de planos de prevenção de longo prazo de potenciais efeitos na saúde das populações nomeadamente para outro tipo de patologias.
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Tese de doutoramento, Farmácia (Química Farmacêutica e Terapêutica), Universidade de Lisboa, Faculdade de Farmácia, 2014
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PURPOSE: To examine risk-taking and risk-perception associations with perceived exertion, pacing and performance in athletes. METHODS: Two experiments were conducted in which risk-perception was assessed using the domain-specific risk-taking (DOSPERT) scale in 20 novice cyclists (Experiment 1) and 32 experienced ultra-marathon runners (Experiment 2). In Experiment 1, participants predicted their pace and then performed a 5 km maximum effort cycling time-trial on a calibrated KingCycle mounted bicycle. Split-times and perceived exertion were recorded every kilometer. In experiment 2, each participant predicted their split times before running a 100 km ultra-marathon. Split-times and perceived exertion were recorded at 7 check-points. In both experiments, higher and lower risk-perception groups were created using median split of DOSPERT scores. RESULTS: In experiment 1, pace during the first km was faster among lower compared to higher risk-perceivers, t(18)=2.0 P=0.03, and faster among higher compared lower risk-takers, t(18)=2.2 P=0.02. Actual pace was slower than predicted pace during the first km in both the higher risk perceivers, t(9)=-4.2 P=0.001, and lower risk-perceivers, t(9)=-1.8 P=0.049. In experiment 2, pace during the first 36 km was faster among lower compared to higher risk-perceivers, t(16)=2.0 P=0.03. Irrespective of risk-perception group, actual pace was slower than predicted pace during the first 18 km, t(16)=8.9 P<0.001, and from 18 to 36 km, t(16)=4.0 P<0.001. In both experiments there was no difference in performance between higher and lower risk-perception groups. CONCLUSIONS: Initial pace is associated with an individual's perception of risk, with low perceptions of risk being associated with a faster starting pace. Large differences between predicted and actual pace suggests the performance template lacks accuracy, perhaps indicating greater reliance on momentary pacing decisions rather than pre-planned strategy.
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Carpooling initiated in America in the 1970s due to the oil crisis. However, over the past years, carpooling has increased significantly across the world. Some countries have created a High Occupancy Vehicle (HOV) lane to encourage commuters not to travel alone. In additional, carpool websites has been developed to facilitate the connection between the commuters, making it possible to create a compatible match in a faster and efficient manner. This project focuses on carpooling, especially in an academic environment since younger people are more likely to choose carpool. Initially, an intense research was made to examine carpool studies that occurred all over the world, following with a research of higher education institutes that use carpooling as a transportation mode. Most websites created carpools by targeting people from a specific country. These commuters have different origins and destinations making it more complicated to create compatible matches. The objective of this project is to develop a system helping teachers and students from an academic environment to create carpool matches. This objective makes it easier to create carpools because these students and teachers have the same destination. During the research, it was essential to explore, as many as possible, existing carpool websites that are available across the world. After this analysis, several sketches were made to develop the layout and structure of the web application that’s being implemented throughout the project. Once the layout was established, the development of the web application was initiated. This project had its ups and downs but it accomplished all the necessary requirements. This project can be accessed on the link: http://ipcacarpool.somee.com. Once the website was up and running, a web-based survey was developed to study the reasons that motivate people to consider carpooling as an alternative to driving alone. To develop this survey was used a tool called Survey Planet. This survey contained 408 respondents, which 391 are students and 17 are teachers. This study concludes that a majority of the respondents don’t carpool, however they will consider carpooling if there was a dedicated parking space. A majority of the respondents that carpool initiated less than a year ago, indicating that this mean of transportation is recent.