930 resultados para exposure time


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Transportation disadvantage has been recognised to be the key source of social exclusion. Therefore an appropriate process is required to investigate and seek to resolve this problem. Currently, determination of Transportation Disadvantage is postulate based on income, poverty and mobility level. Transportation disadvantage may best regard be based on accessibility perspectives as they represent inability of the individual to access desired activities. This paper attempts to justify a process in determining transportation disadvantage by incorporating accessibility and social transporation conflict as the essence of a framework. The framework embeds space time organisation within the dimension of accessibility to identify a rigorous definition of transportation disadvantage. In developing the framework, the definition, dimension, component and measure of accessibility were scrutinised. The findings suggest the definition and dimension are the significant approach of research to evaluate travel experience of the disadvantaged. Concurrently, location accessibility measures will be incorprated to strenghten the determination of accessibility level. Literature review in social exclusion and mobility-related exclusion identified the dimension and source of transportation disadvantage. It was revealed that the appropriate approach to justify trasnportation disadvantaged is to incorporate space-time organisation within the studied components. The suggested framework is an inter-related process consisting of component of accessibility; individual, networking (transport system) and activities (destination). The integration and correlation among the components shall determine the level of transportation disadvantage. Prior findings are used to retrieve the spatial distribution of transportation disadvantaged and appropriate policies are developed to resolve the problems.

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Purpose Increased physical activity in colorectal cancer patients is related to improved recurrence free and overall survival. Psychological distress after cancer may place patients at risk of reduced physical activity; but paradoxically also act as a motivator for positive lifestyle change. The relationship between psychological distress and physical activity after cancer over time has not been described. Methods A prospective survey of 1966 (57% response) colorectal cancer survivors assessed the psychological distress variables of anxiety, depression, somatisation, cancer threat appraisal as predictors of physical activity five, 12, 24 and 36 months post-diagnosis 978 respondents had valid data for all time points. Results Higher somatisation was associated with greater physical inactivity (Relative risk ratio (RRR) =1.12; 95% CI=[1.1, 1.2]) and insufficient physical activity (RRR=1.05; [0.90, 1.0]). Respondents with a more positive appraisal of their cancer were significantly (p=0.031) less likely to be inactive (RRR=0.95; [0.90, 1.0]) or insufficiently active (RRR=0.96). Fatigued and obese respondents and current smokers were more inactive. Respondents whose somatisation increased between two time periods were less likely to increase their physical activity over the same period (p<0.001). Respondents with higher anxiety at one time period were less likely to have increased their activity at the next assessment (p=0.004). There was no association between depression and physical activity. Conclusions Cancer survivors who experience somatisation and anxiety are at greater risk of physical inactivity. The lack of a clear relationship between higher psychological distress and increasing physical activity argues against distress as a motivator to exercise in these patients.

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This paper examines a sequence of asynchronous interaction on the photosharing website, Flickr. In responding to a call for a focus on the performative aspects of online annotation (Wolff & Neuwirth, 2001), we outline and apply an interaction order approach to identify temporal and cultural aspects of the setting that provide for commonality and sharing. In particular, we study the interaction as a feature of a synthetic situation (Knorr Cetina, 2009) focusing on the requirements of maintaining a sense of an ongoing discussion online. Our analysis suggests that the rhetorical system of the Flickr environment, its appropriation by participants as a context for bounded activities, and displays of commonality, affiliation, and shared access provide for a common sense of participation in a time envelope. This, in turn, is argued to be central to new processes of consociation (Schutz, 1967; Zhao, 2004) occurring in the life world of Web 2.0 environments.

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Purpose: Television viewing time, independent of leisure-time physical activity, has cross-sectional relationships with the metabolic syndrome and its individual components. We examined whether baseline and five-year changes in self-reported television viewing time are associated with changes in continuous biomarkers of cardio-metabolic risk (waist circumference, triglycerides, high density lipoprotein cholesterol, systolic and diastolic blood pressure, fasting plasma glucose; and a clustered cardio-metabolic risk score) in Australian adults. Methods: AusDiab is a prospective, population-based cohort study with biological, behavioral, and demographic measures collected in 1999–2000 and 2004–2005. Non-institutionalized adults aged ≥ 25 years were measured at baseline (11,247; 55% of those completing an initial household interview); 6,400 took part in the five-year follow-up biomedical examination, and 3,846 met the inclusion criteria for this analysis. Multiple linear regression analysis was used and unstandardized B coefficients (95% CI) are provided. Results: Baseline television viewing time (10 hours/week unit) was not significantly associated with change in any of the biomarkers of cardio-metabolic risk. Increases in television viewing time over five years (10 hours/week unit) were associated with increases in: waist circumference (cm) (men: 0.43 (0.08, 0.78), P = 0.02; women: 0.68 (0.30, 1.05), P <0.001), diastolic blood pressure (mmHg) (women: 0.47 (0.02, 0.92), P = 0.04), and the clustered cardio-metabolic risk score (women: 0.03 (0.01, 0.05), P = 0.007). These associations were independent of baseline television viewing time and baseline and change in physical activity and other potential confounders. Conclusion: These findings indicate that an increase in television viewing time is associated with adverse cardio-metabolic biomarker changes. Further prospective studies using objective measures of several sedentary behaviors are required to confirm causality of the associations found.

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The epidemic of obesity is impacting an increasing proportion of children, adolescents and adults with a common feature being low levels of physical activity (PA). Despite having more knowledge than ever before about the benefits of PA for health and the growth and development of youngsters, we are only paying lip-service to the development of motor skills in children. Fun, enjoyment and basic skills are the essential underpinnings of meaningful participation in PA. A concurrent problem is the reported increase in sitting time with the most common sedentary behaviors being TV viewing and other screen-based games. Limitations of time have contributed to a displacement of active behaviors with inactive pursuits, which has contributed to reductions in activity energy expenditure. To redress the energy imbalance in overweight and obese children, we urgently need out-of-the-box multisectoral solutions. There is little to be gained from a shame and blame mentality where individuals, their parents, teachers and other groups are singled out as causes of the problem. Such an approach does little more than shift attention from the main game of prevention and management of the condition, which requires a concerted, whole-of-government approach (in each country). The failure to support and encourage all young people to participate in regular PA will increase the chance that our children will live shorter and less healthy lives than their parents. In short, we need novel environmental approaches to foster a systematic increase in PA. This paper provides examples of opportunities and challenges for PA strategies to prevent obesity with a particular emphasis on the school and home settings.

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Technological and societal change, along with organisational and market change (driven by contracting-out and privatisation), are “creating a new generation of infrastructures” [1]. While inter-organisational contractual arrangements can improve maintenance efficiency through consistent and repeatable patterns of action - unanticipated difficulties in implementation can reduce the performance of these arrangements. When faced with unsatisfactory performance of contracting-out arrangements, government organisations may choose to adapt and change these arrangements over time, with the aim of improving performance. This paper enhances our understanding of ‘next generation infrastructures’ by examining adaptation of the organisational arrangements for the maintenance of these assets, in a case study spanning 20 years.

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Reports on the reemergence of a concern with planning city centers as focal points in the 1980s. De-industrialization of older industrial areas; Revalorization of city center sites; Emergence of city-to-city competitiveness at a national and supranational level.

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Youth population is increasing explosively particularly in developing countries as a result of rapid urbanization. This increase is bringing large number of social and economic problems. For instance the impacts of job and training availability, and the physical, social and cultural quality of urban environment on young people are enormous, and affect their health, lifestyles, and well-being (Gleeson and Sipe 2006). Besides this, globalization and technological developments are affecting youth in urban areas in all parts of the world, both positively and negatively (Robertson 1995). The rapidly advancing information and communications technologies (ICTs) helps in addressing social and economic problems caused by the rapid growth of urban youth populations in developing countries. ICTs offer opportunities to young people for learning, skill development and employment. But there are downsides: young people in many developing countries lack of having broad access to these new technologies, they are vulnerable to global market changes, and ICTs link them into global cultures which promote consumer goods, potentially eroding local cultures and community values (Manacorda and Petrongolo 1999). However we believe that the positives outweigh such negatives. At the beginning of the twenty-first century, the world’s young population number more than they ever have. There are over a billion young people between the ages of 15 and 24, which 85 per cent of them live in developing countries and mainly in urban environments. Many of these young people are in the process of making, or have already made, the transition from school to work. During the last two decades all around the world, these young people, as new workers, have faced a number of challenges associated with globalization and technological advances on labour markets (United Nations 2004). The continuous decrease in the manufacturing employment is made many of the young people facing three options: getting jobs in the informal economy with insecurity and poor wages and working conditions, or getting jobs in the low-tier service industries, or developing their vocational skills to benefit from new opportunities in the professional and advanced technical/knowledge sectors. Moreover in developing countries a large portion of young people are not even lucky enough to choose among any of these options, and consequently facing long-term unemployment, which makes them highly vulnerable. The United Nations’ World Youth Employment report (2004) indicates that in almost all countries, females tend to be far more vulnerable than males in terms of long-term unemployment, and young people who have advanced qualifications are far less likely to experience long-term unemployment than others. In the limited opportunities of the formal labour market, those with limited vocational skills resort to forced entrepreneurship and selfemployment in the informal economy, often working for low pay under hazardous conditions, with only few prospects for the future (United Nations 2005a). The International Labour Organization’s research (2004) revealed that the labour force participation rates for young people decreased by almost four per cent (which is equivalent of 88 million young people) between 1993 and 2003. This is largely as a result of the increased number of young people attending school, high overall unemployment rates, and the fact that some young people gave up any hope of finding work and dropped out of the labour market. At the regional level, youth unemployment was highest in Middle East and North Africa (MENA) (25.6%) and sub-Saharan Africa (21%) and lowest in East Asia (7%) and the industrialized economies(13.4%) (International Labour Organization 2004). The youth in economically disadvantaged regions (e.g. the MENA region) face many challenges in education and training that delivers them the right set of skills and knowledge demanded by the labour market. As a consequence, the transition from school to work is mostly unsuccessful and young population end up either unemployed or underemployed in the informal sectors (United Nations 2005b). Unemployment and lack of economic prospects of the urban youth are pushing many of them into criminal acts, excessive alcohol use, substance addiction, and also in many cases resulting in processes of social or political violence (Fernandez-Maldonado 2004; United Nations 2005a). Long-term unemployment leads young people in a process of marginalisation and social exclusion (United Nations 2004). The sustained high rates of long-term youth unemployment have a number of negative effects on societies. First, it results in countries failing to take advantage of the human resources to increase their productive potential, at a time of transition to a globalized world that inexorably demands such leaps in productive capacity. Second, it reinforces the intergenerational transmission of poverty. Third, owing to the discrepancy between more education and exposure to the mass media and fewer employment opportunities, it may encourage the spread of disruptive behaviours, recourse to illegal alternatives for generating income and the loss of basic societal values, all of which erode public safety and social capital. Fourth, it may trigger violent and intractable political conflicts. And lastly, it may exacerbate intergenerational conflicts when young people perceive a lack of opportunity and meritocracy in a system that favours adults who have less formal education and training but more wealth, power and job stability (Hopenhayn 2002). To assist in addressing youth’s skill training and employment problems this paper scrutinises useful international practices, policies, initiatives and programs targeting youth skill training, particularly in ICTs. The MENA national governments and local authorities could consider implementing similar initiative and strategies to address some of the youth employment issues. The broader aim of this paper is to investigate the successful practice and strategies for the information and communication related income generation opportunities for young people to: promote youth entrepreneurship; promote public-private partnerships; target vulnerable groups of young people; narrow digital divide; and put young people in charge. The rest of this paper is organised in five parts. First, the paper provides an overview of the literature on the knowledge economy, skill, education and training issues. Secondly, it reviews the role of ICTs for vocational skill development and employability. Thirdly, it discusses the issues surrounding the development of the digital divide. Fourthly, the paper underlines types and the importance of developing ICT initiatives targeting young people, and reviews some of the successful policy implementations on ICT-based initiatives from both developed and developing countries that offer opportunities to young people for learning, skill development and employment. Then the paper concludes by providing useful generalised recommendations for the MENA region countries and cities in: advocating possible opportunities for ICT generated employment for young people; and discussing how ICT policies could be modified and adopted to meet young people’s needs.

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This paper investigates the robust H∞ control for Takagi-Sugeno (T-S) fuzzy systems with interval time-varying delay. By employing a new and tighter integral inequality and constructing an appropriate type of Lyapunov functional, delay-dependent stability criteria are derived for the control problem. Because neither any model transformation nor free weighting matrices are employed in our theoretical derivation, the developed stability criteria significantly improve and simplify the existing stability conditions. Also, the maximum allowable upper delay bound and controller feedback gains can be obtained simultaneously from the developed approach by solving a constrained convex optimization problem. Numerical examples are given to demonstrate the effectiveness of the proposed methods.

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While increasing numbers of young high school students engage in part-time work, there is no consensus about its impact on educational outcomes. Indeed this field has had a dearth of research. The present paper presents a review of recent research, primarily from Australia and the US, although it is acknowledged that there are considerable contextual differences. Suggestions for school counsellors to harness the students’ experiences to assist in educational and career decision-making are presented.

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Financial processes may possess long memory and their probability densities may display heavy tails. Many models have been developed to deal with this tail behaviour, which reflects the jumps in the sample paths. On the other hand, the presence of long memory, which contradicts the efficient market hypothesis, is still an issue for further debates. These difficulties present challenges with the problems of memory detection and modelling the co-presence of long memory and heavy tails. This PhD project aims to respond to these challenges. The first part aims to detect memory in a large number of financial time series on stock prices and exchange rates using their scaling properties. Since financial time series often exhibit stochastic trends, a common form of nonstationarity, strong trends in the data can lead to false detection of memory. We will take advantage of a technique known as multifractal detrended fluctuation analysis (MF-DFA) that can systematically eliminate trends of different orders. This method is based on the identification of scaling of the q-th-order moments and is a generalisation of the standard detrended fluctuation analysis (DFA) which uses only the second moment; that is, q = 2. We also consider the rescaled range R/S analysis and the periodogram method to detect memory in financial time series and compare their results with the MF-DFA. An interesting finding is that short memory is detected for stock prices of the American Stock Exchange (AMEX) and long memory is found present in the time series of two exchange rates, namely the French franc and the Deutsche mark. Electricity price series of the five states of Australia are also found to possess long memory. For these electricity price series, heavy tails are also pronounced in their probability densities. The second part of the thesis develops models to represent short-memory and longmemory financial processes as detected in Part I. These models take the form of continuous-time AR(∞) -type equations whose kernel is the Laplace transform of a finite Borel measure. By imposing appropriate conditions on this measure, short memory or long memory in the dynamics of the solution will result. A specific form of the models, which has a good MA(∞) -type representation, is presented for the short memory case. Parameter estimation of this type of models is performed via least squares, and the models are applied to the stock prices in the AMEX, which have been established in Part I to possess short memory. By selecting the kernel in the continuous-time AR(∞) -type equations to have the form of Riemann-Liouville fractional derivative, we obtain a fractional stochastic differential equation driven by Brownian motion. This type of equations is used to represent financial processes with long memory, whose dynamics is described by the fractional derivative in the equation. These models are estimated via quasi-likelihood, namely via a continuoustime version of the Gauss-Whittle method. The models are applied to the exchange rates and the electricity prices of Part I with the aim of confirming their possible long-range dependence established by MF-DFA. The third part of the thesis provides an application of the results established in Parts I and II to characterise and classify financial markets. We will pay attention to the New York Stock Exchange (NYSE), the American Stock Exchange (AMEX), the NASDAQ Stock Exchange (NASDAQ) and the Toronto Stock Exchange (TSX). The parameters from MF-DFA and those of the short-memory AR(∞) -type models will be employed in this classification. We propose the Fisher discriminant algorithm to find a classifier in the two and three-dimensional spaces of data sets and then provide cross-validation to verify discriminant accuracies. This classification is useful for understanding and predicting the behaviour of different processes within the same market. The fourth part of the thesis investigates the heavy-tailed behaviour of financial processes which may also possess long memory. We consider fractional stochastic differential equations driven by stable noise to model financial processes such as electricity prices. The long memory of electricity prices is represented by a fractional derivative, while the stable noise input models their non-Gaussianity via the tails of their probability density. A method using the empirical densities and MF-DFA will be provided to estimate all the parameters of the model and simulate sample paths of the equation. The method is then applied to analyse daily spot prices for five states of Australia. Comparison with the results obtained from the R/S analysis, periodogram method and MF-DFA are provided. The results from fractional SDEs agree with those from MF-DFA, which are based on multifractal scaling, while those from the periodograms, which are based on the second order, seem to underestimate the long memory dynamics of the process. This highlights the need and usefulness of fractal methods in modelling non-Gaussian financial processes with long memory.

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Unresolved painful emotional experiences such as bereavement, trauma and disturbances in core relationships, are common presenting problems for clients of psychodrama or psychotherapy more generally. Emotional pain is experienced as a shattering of the sense of self and disconnection from others and, when unresolved, produces avoidant responses which inhibit the healing process. There is agreement across therapeutic modalities that exposure to emotional experience can increase the efficacy of therapeutic interventions. Moreno proposes that the activation of spontaneity is the primary curative factor in psychodrama and that healing occurs when the protagonist (client) engages with his or her wider social system and develops greater flexibility in response to that system. An extensive case-report literature describes the application of the psychodrama method in healing unresolved painful emotional experiences, but there is limited empirical research to verify the efficacy of the method or to identify the processes that are linked to therapeutic change. The purpose of this current research was to construct a model of protagonist change processes that could extend psychodrama theory, inform practitioners’ therapeutic decisions and contribute to understanding the common factors in therapeutic change. Four studies investigated protagonist processes linked to in-session resolution of painful emotional experiences. Significant therapeutic events were analysed using recordings and transcripts of psychodrama enactments, protagonist and director recall interviews and a range of process and outcome measures. A preliminary study (3 cases) identified four themes that were associated with helpful therapeutic events: enactment, the working alliance with the director and with group members, emotional release or relief and social atom repair. The second study (7 cases) used Comprehensive Process Analysis (CPA) to construct a model of protagonists’ processes linked to in-session resolution. This model was then validated across four more cases in Study 3. Five meta-processes were identified: (i) a readiness to engage in the psychodrama process; (ii) re-experiencing and insight; (iii) activating resourcefulness; (iv) social atom repair with emotional release and (v) integration. Social atom repair with emotional release involved deeply experiencing a wished-for interpersonal experience accompanied by a free flowing release of previously restricted emotion and was most clearly linked to protagonists’ reports of reaching resolution and to post session improvements in interpersonal relationships and sense of self. Acceptance of self in the moment increased protagonists’ capacity to generate new responses within each meta-process and, in resolved cases, there was evidence of spontaneity developing over time. The fourth study tested Greenberg’s allowing and accepting painful emotional experience model as an alternative explanation of protagonist change. The findings of this study suggested that while the process of allowing emotional pain was present in resolved cases, Greenberg’s model was not sufficient to explain the processes that lead to in-session resolution. The protagonist’s readiness to engage and activation of resourcefulness appear to facilitate the transition from problem identification to emotional release. Furthermore, experiencing a reparative relationship was found to be central to the healing process. This research verifies that there can be in-session resolution of painful emotional experience during psychodrama and protagonists’ reports suggest that in-session resolution can heal the damage to the sense of self and the interpersonal disconnection that are associated with unresolved emotional pain. A model of protagonist change processes has been constructed that challenges the view of psychodrama as a primarily cathartic therapy, by locating the therapeutic experience of emotional release within the development of new role relationships. The five meta-processes which are described within the model suggest broad change principles which can assist practitioners to make sense of events as they unfold and guide their clinical decision making in the moment. Each meta-process was linked to specific post-session changes, so that the model can inform the development of therapeutic plans for individual clients and can aid communication for practitioners when a psychodrama intervention is used for a specific therapeutic purpose within a comprehensive program of therapy.

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Concern regarding the health effects of indoor air quality has grown in recent years, due to the increased prevalence of many diseases, as well as the fact that many people now spend most of their time indoors. While numerous studies have reported on the dynamics of aerosols indoors, the dynamics of bioaerosols in indoor environments are still poorly understood and very few studies have focused on fungal spore dynamics in indoor environments. Consequently, this work investigated the dynamics of fungal spores in indoor air, including fungal spore release and deposition, as well as investigating the mechanisms involved in the fungal spore fragmentation process. In relation to the investigation of fungal spore dynamics, it was found that the deposition rates of the bioaerosols (fungal propagules) were in the same range as the deposition rates of nonbiological particles and that they were a function of their aerodynamic diameters. It was also found that fungal particle deposition rates increased with increasing ventilation rates. These results (which are reported for the first time) are important for developing an understanding of the dynamics of fungal spores in the air. In relation to the process of fungal spore fragmentation, important information was generated concerning the airborne dynamics of the spores, as well as the part/s of the fungi which undergo fragmentation. The results obtained from these investigations into the dynamics of fungal propagules in indoor air significantly advance knowledge about the fate of fungal propagules in indoor air, as well as their deposition in the respiratory tract. The need to develop an advanced, real-time method for monitoring bioaerosols has become increasingly important in recent years, particularly as a result of the increased threat from biological weapons and bioterrorism. However, to date, the Ultraviolet Aerodynamic Particle Sizer (UVAPS, Model 3312, TSI, St Paul, MN) is the only commercially available instrument capable of monitoring and measuring viable airborne micro-organisms in real-time. Therefore (for the first time), this work also investigated the ability of the UVAPS to measure and characterise fungal spores in indoor air. The UVAPS was found to be sufficiently sensitive for detecting and measuring fungal propagules. Based on fungal spore size distributions, together with fluorescent percentages and intensities, it was also found to be capable of discriminating between two fungal spore species, under controlled laboratory conditions. In the field, however, it would not be possible to use the UVAPS to differentiate between different fungal spore species because the different micro-organisms present in the air may not only vary in age, but may have also been subjected to different environmental conditions. In addition, while the real-time UVAPS was found to be a good tool for the investigation of fungal particles under controlled conditions, it was not found to be selective for bioaerosols only (as per design specifications). In conclusion, the UVAPS is not recommended for use in the direct measurement of airborne viable bioaerosols in the field, including fungal particles, and further investigations into the nature of the micro-organisms, the UVAPS itself and/or its use in conjunction with other conventional biosamplers, are necessary in order to obtain more realistic results. Overall, the results obtained from this work on airborne fungal particle dynamics will contribute towards improving the detection capabilities of the UVAPS, so that it is capable of selectively monitoring and measuring bioaerosols, for which it was originally designed. This work will assist in finding and/or improving other technologies capable of the real-time monitoring of bioaerosols. The knowledge obtained from this work will also be of benefit in various other bioaerosol applications, such as understanding the transport of bioaerosols indoors.