903 resultados para three-body trajectory
Resumo:
Previous research suggests that soil organic C pools may be a feature of semiarid regions that are particularly sensitive to climatic changes. We instituted an 18-mo experiment along an elevation gradient in northern Arizona to evaluate the influence of temperature, moisture, and soil C pool size on soil respiration. Soils, from underneath different free canopy types and interspaces of three semiarid ecosystems, were moved upslope and/or downslope to modify soil climate. Soils moved downslope experienced increased temperature and decreased precipitation, resulting in decreased soil moisture and soil respiration las much as 23 acid 20%, respectively). Soils moved upslope to more mesic, cooler sites had greater soil water content and increased rates of soil respiration las much as 40%), despite decreased temperature. Soil respiration rates normalized for total C were not significantly different within any of the three incubation sites, indicating that under identical climatic conditions, soil respiration is directly related to soil C pool size for the incubated soils. Normalized soil respiration rates between sites differed significantly for all soil types and were always greater for soils incubated under more mesic, but cooler, conditions. Total soil C did not change significantly during the experiment, but estimates suggest that significant portions of the rapidly cycling C pool were lost. While long-term decreases in aboveground and belowground detrital inputs may ultimately be greater than decreased soil respiration, the initial response to increased temperature and decreased precipitation in these systems is a decrease in annual soil C efflux.
Resumo:
A substantial body of research is focused on understanding the relationships between socio-demographics, land-use characteristics, and mode specific attributes on travel mode choice and time-use patterns. Residential and commercial densities, inter-mixing of land uses, and route directness in conjunction with transportation performance characteristics interact to influence accessibility to destinations as well as time spent traveling and engaging in activities. This study uniquely examines the activity durations undertaken for out-of-home subsistence; maintenance, and discretionary activities. Also examined are total tour durations (summing all activity categories within a tour). Cross-sectional activities are obtained from household activity travel survey data from the Atlanta Metropolitan Region. Time durations allocated to weekdays and weekends are compared. The censoring and endogeneity between activity categories and within individuals are captured using multiple equations Tobit models. The analysis and modeling reveal that land-use characteristics such as net residential density and the number of commercial parcels within a kilometer of a residence are associated with differences in weekday and weekend time-use allocations. Household type and structure are significant predictors across the three activity categories, but not for overall travel times. Tour characteristics such as time-of-day and primary travel mode of the tours also affect traveler's out-of-home activity-tour time-use patterns.
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The multi-criteria decision making methods, Preference METHods for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GAIA), and the two-way Positive Matrix Factorization (PMF) receptor model were applied to airborne fine particle compositional data collected at three sites in Hong Kong during two monitoring campaigns held from November 2000 to October 2001 and November 2004 to October 2005. PROMETHEE/GAIA indicated that the three sites were worse during the later monitoring campaign, and that the order of the air quality at the sites during each campaign was: rural site > urban site > roadside site. The PMF analysis on the other hand, identified 6 common sources at all of the sites (diesel vehicle, fresh sea salt, secondary sulphate, soil, aged sea salt and oil combustion) which accounted for approximately 68.8 ± 8.7% of the fine particle mass at the sites. In addition, road dust, gasoline vehicle, biomass burning, secondary nitrate, and metal processing were identified at some of the sites. Secondary sulphate was found to be the highest contributor to the fine particle mass at the rural and urban sites with vehicle emission as a high contributor to the roadside site. The PMF results are broadly similar to those obtained in a previous analysis by PCA/APCS. However, the PMF analysis resolved more factors at each site than the PCA/APCS. In addition, the study demonstrated that combined results from multi-criteria decision making analysis and receptor modelling can provide more detailed information that can be used to formulate the scientific basis for mitigating air pollution in the region.
Resumo:
As the problems involving infrastructure delivery have become more complex and contentious, there has been an acknowledgement that these problems cannot be resolved by any one body working alone. This understanding has driven multi-sectoral collaboration and has led to an expansion of the set of actors, including stakeholders, who are now involved in delivery of infrastructure projects and services. However, more needs to be understood about how to include stakeholders in these processes and ways of developing the requisite combination of stakeholders to achieve effective outcomes. This thesis draws on stakeholder theory and governance network theory to obtain insights into how three multi-level networks within the Roads Alliance in Queensland engage with stakeholders in the delivery of complex and sensitive infrastructure services and projects. New knowledge about stakeholders will be obtained by testing a model of Stakeholder Salience and Engagement which combines and extends the stakeholder identification and salience theory, ladder of stakeholder management and engagement and the model of stakeholder engagement and moral treatment of stakeholders. By applying this model, the broad research question: “Who or what decides how stakeholders are engaged by governance networks delivering public outcomes?” will be addressed. The case studies will test a theoretical model of stakeholder salience and engagement which links strategic decisions about stakeholder salience with the quality and quantity of engagement strategies for engaging different types of stakeholders. A multiple embedded case study design has been selected as the overall approach to explore, describe, explain and evaluate how stakeholder engagement occurs in three governance networks delivering road infrastructure in Queensland. The research design also incorporates a four stage approach to data collection: observations, stakeholder analysis, telephone survey questionnaire and semi-structured interviews. The outcomes of this research will contribute to and extend stakeholder theory by showing how stakeholder salience impacts on decisions about the types of engagement processes implemented. Governance network theory will be extended by showing how governance networks interact with stakeholders through the concepts of stakeholder salience and engagement. From a practical perspective this research will provide governance networks with an indication of how to optimise engagement with different types of stakeholders. 2
Resumo:
The structures of bis(guanidinium)rac-trans-cyclohexane-1,2-dicarboxylate, 2(CH6N3+) C8H10O4- (I), guanidinium 3-carboxybenzoate monohydrate CH6N3+ C8H5O4- . H2O (II) and bis(guanidinium) benzene-1,4-dicarboxylate trihydrate, 2(CH6N3+) C8H4O4^2- . 3H2O (III) have been determined and the hydrogen bonding in each examined. All three compounds form three-dimensional hydrogen-bonded framework structures. In anhydrous (I), both guanidinium cations give classic cyclic R2/2(8) N--H...O,O'(carboxyl) and asymmetric cyclic R1/2(6) hydrogen-bonding interactions while one cation gives an unusual enlarged cyclic interaction with O acceptors of separate ortho-related carboxyl groups [graph set R2/2(11)]. Cations and anions also associate across inversion centres giving cyclic R2/4(8) motifs. In the 1:1 guanidinium salt (II), the cation gives two separate cyclic R1/2(6) interactions, one with a carboxyl O-acceptor, the other with the water molecule of solvation. The structure is unusual in that both carboxyl groups give short inter-anion O...H...O contacts, one across a crystallographic inversion centre [2.483(2)\%A], the other about a two-fold axis of rotation [2.462(2)\%A] with a half-occupancy hydrogen delocalized on the symmetry element in each. The water molecule links the cation--anion ribbon structures into a three-dimensional framework. In (III), the repeating molecular unit comprises a benzene-1,4-dicarboxylate dianion which lies across a crystallographic inversion centre, two guanidinium cations and two water molecules of solvation (each set related by two-fold rotational symmetry), and a single water molecule which lies on a two-fold axis. Each guanidinium cation gives three types of cyclic interactions with the dianions: one R^1^~2~(6), the others R2/3(8) and R3/3(10) (both of these involving the water molecules), giving a three-dimensional structure through bridges down the b cell direction. The water molecule at the general site also forms an unusual cyclic R2/2(4) homodimeric association across an inversion centre [O--H...O, 2.875(2)\%A]. The work described here provides further examples of the common cyclic guanidinium cation...carboxylate anion hydrogen-bonding associations as well as featuring other less common cyclic motifs.
Resumo:
The structures of the anhydrous 1:1 proton-transfer compounds of isonipecotamide (piperidine-4-carboxamide) with the three isomeric mononitro-substituted benzoic acids and 3,5-dinitrobenzoic acid, namely 4-carbamoylpiperidinium 2-nitrobenzoate (I), 4-carbamoylpiperidinium 3-nitrobenzoate (II), 4-carbamoylpiperidinium 4-nitrobenzoate (III), (C6H13N2O+ C7H4NO4-) and 4-carbamoylpiperidinium 3,5-dinitrobenzoate (IV) (C6H13N2O+ C7H5N2O6-)respectively, have been determined at 200 K. All salts form hydrogen-bonded structures: three-dimensional in (I), two-dimensional in (II) and (III) and one-dimensional in (IV). Featured in the hydrogen bonding of three of these [(I), (II) and (IV)] is the cyclic head-to-head amide--amide homodimer motif [graph set R2/2~(8)] through a duplex N---H...O association, the dimer then giving structure extension via either piperidinium or amide H-donors and carboxylate-O and in some examples [(II) and (IV)], nitro-O atom acceptors. In (I), the centrosymmetric amide-amide homodimers are expanded laterally through N-H...O hydrogen bonds via cyclic R2/4(8) interactions forming ribbons which extend along the c cell direction. These ribbons incorporate the 2-nitrobenzoate cations through centrosymmetric cyclic piperidine N-H...O(carboxyl) associations [graph set R4/4(12)], giving inter-connected sheets in the three-dimensional structure. In (II) in which no amide-amide homodimer is present, duplex piperidinium N-H...O(amide) hydrogen-bonding homomolecular associations [graph set R2/2(14)] give centrosymmetric head-to-tail dimers. Structure extension occurs through hydrogen-bonding associations between both the amide H-donors and carboxyl and nitro O-acceptors as well as a three-centre piperidinium N-H...O,O'(carboxyl) cyclic R2/1(4) association giving the two-dimensional network structure. In (III), the centrosymmetric amide-amide dimers are linked through the two carboxyl O-atom acceptors of the anions via bridging piperidinium and amide N-H...O,O'...H-N(amide) hydrogen bonds giving the two-dimensional sheet structure which features centrosymmetric cyclic R4/4(12) associations. In (IV), the amide-amide dimer is also centrosymmetric with the dimers linked to the anions through amide N-H...O(nitro) interactions. The piperidinium groups extend the structure into one-dimensional ribbons via N-H...O(carboxyl) hydrogen bonds. The structures reported here further demonstrate the utility of the isonipecotamide cation in molecular assembly and highlight the efficacy of the cyclic R2/2(8) amide-amide hydrogen-bonding homodimer motif in this process and provide an additional homodimer motif type in the head-to-tail R2/2(14) association.
Resumo:
Prolific British author/illustrator Anthony Browne both participates in the classic fairy-tale tradition and appropriates its cultural capital, ultimately undertaking a process of self-canonisation alongside the dissemination of fairy tales. In reading Browne’s Hansel and Gretel (1981), The Tunnel (1989) and Into the Forest (2004), a trajectory emerges that moves from broadly intertextual to more exclusively self-referential modes of representation which reward readers of “Anthony Browne”, rather than readers of “fairy tales”. All three books depict ‘babes in the woods’ stories wherein child characters must negotiate some form of threat outside the home in order to return home safely. Thus, they represent childhood agency. However, these visions of agency are ultimately subordinated to logics of capital, which means that child readers of Browne’s fairy-tale books are overtly invited to identify with children who act, but are interpellated as privileged if they ‘know’. Bourdieu’s model of ‘cultural capital’ offers a lens for considering Browne’s production of ‘value’ for his own works within a broader cultural landscape which privileges literary fairy tales as a register of juvenile cultural competency. If cultural capital can be formulated most simply as the symbolic exchange value of approved modes of knowing and being, it is clearly helpful when trying to unpack logics of meaning within heavily intertextual or citational texts. It is also helpful thinking about what kinds of stories we as a culture choose to disseminate, choose to privilege, or choose to suppress. Zipes notes of fairy tales that, “the genre itself becomes a kind of institute that is involved in the socialization and acculturation of readers” (22). He elaborates that, “We initiate readers and expect them to learn the fairy-tale code as part of our responsibility in the civilizing process” (Zipes 29), so it is little wonder that Tatar describes fairy tales as “a vital part of our cultural capital” (xix). Although Browne is clearly interested in literary fairy tales, the most obvious strategies of self-canonisation take place in Browne’s work not in words but in pictures: hidden in plain sight, as illustration becomes self-reflexive citation.
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The purpose of this study is to contribute to the cross-disciplinary body of literature of identity and organisational culture. This study empirically investigated the Hatch and Schultz (2002) Organisational Identity Dynamics (OID) model to look at linkages between identity, image, and organisational culture. This study used processes defined in the OID model as a theoretical frame by which to understand the relationships between actual and espoused identity manifestations across visual identity, corporate identity, and organisational identity. The linking processes of impressing, mirroring, reflecting, and expressing were discussed at three unique levels in the organisation. The overarching research question of How does the organisational identity dynamics process manifest itself in practice at different levels within an organisation? was used as a means of providing empirical understanding to the previously theoretical OID model. Case study analysis was utilised to provide exploratory data across the organisational groups of: Level A - Senior Marketing and Corporate Communications Management, Level B - Marketing and Corporate Communications Staff, and Level C - Non-Marketing Managers and Employees. Data was collected via 15 in-depth interviews with documentary analysis used as a supporting mechanism to provide triangulation in analysis. Data was analysed against the impressing, mirroring, reflecting, and expressing constructs with specific criteria developed from literature to provide a detailed analysis of each process. Conclusions revealed marked differences in the ways in which OID processes occurred across different levels with implications for the ways in which VI, CI, and OI interact to develop holistic identity across organisational levels. Implications for theory detail the need to understand and utilise cultural understanding in identity programs as well as the value in developing identity communications which represent an actual rather than an espoused position.
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This study reports on the impact of a "drink driving education program" taught to grade ten high school students. The program which involves twelve lessons uses strategies based on the Ajzen and Madden theory of planned behavior. Students were trained to use alternatives to drink driving and passenger behaviors. One thousand seven hundred and seventy-four students who had been taught the program in randomly assigned control and intervention schools were followed up three years later. There had been a major reduction in drink driving behaviors in both intervention and control students. In addition to this cohort change there was a trend toward reduced drink driving in the intervention group and a significant reduction in passenger behavior in this group. Readiness to use alternatives suggested that the major impact of the program was on students who were experimenting with the behavior at the time the program was taught. The program seems to have optimized concurrent social attitude and behavior change.
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This analysis of housing experiences and aspirations in three remote Indigenous settlements in Australia (Mimili, Maningrida and Palm Island) reveals extreme liveability problems directly related to the scale and form of housing provision. Based upon field visits to each of the settlements and extensive interviews with residents and local housing and community officers, the paper analyses two aspects of living in such housing conditions at two spatial scales, the layout of the settlement and the design of individual houses. The failings at both scales are shown to be the fault of a dysfunctional housing system that is only recently been addressed.
Resumo:
The workplace is evolving and the predicted impact of demographic changes (Salt, 2009; Taylor, 2005) has seen organisations focus on strategic workforce planning. As part of this, many organisations have established or expanded formalised graduate programs to attract graduates and transition them effectively into organisations (McDermott, Mangan, & O'Connor, 2005; Terjesen, Freeman, & Vinnicombe, 2007). The workplace context is also argued to be changing because of the divergence in preferences and priorities across the different generations in the workplace - a topic which is prolific in the popular culture media but is yet to be fully developed in the academic literature (Jorgenson, 2003). The public sector recruits large numbers of graduates and maintains well established graduate programs. Like the workplace context, the public sector is seen to be undergoing a transition to more closely align its practices and processes with that of the private sector (Haynes & Melville Jones, 1999; N. Preston, 1995). Consequently, questions have been raised as to how new workforce entrants see the public sector and its associated attractiveness as an employment option. This research draws together these issues and reviews the formation of, and change in, the psychological contracts of graduates across ten Queensland public sector graduate programs. To understand the employment relationship, the theories of psychological contract and public service motivation are utilised. Specifically, this research focuses on graduates' and managers' expectations over time, the organisational perspective of the employment relationship and how ideology influences graduates' psychological contract. A longitudinal mixed method design, involving individual interviews and surveys, is employed along with significant researcher-practitioner collaboration throughout the research process. A number of important qualitative and quantitative findings arose from this study and there was strong triangulation between results from the two methods. Prior to starting with the organisation, graduates found it difficult to articulate their expectations; however, organisational experience rapidly brought these to the fore. Of the expectations that became salient, most centred on their relationship with their supervisor. Without experience and quality information on which to base their expectations, graduates tended to over-rely on sectoral stereotypes which negatively impacted their psychological contracts. Socialisation only limited affected graduates' psychological contracts and public service motivation. The graduate survey, measured thrice throughout the first 12 months of the graduate program, revealed that the psychological contract and public service motivation results followed a similar trajectory of beginning at mediocre levels, declining between times one and two and increasing between times two and three (although this is not back to original levels). Graduates attributed these to a number of sectoral, organisational, team, supervisory and individual factors. On a theoretical level, this research provides support for the notion of ideology within the psychological contract although it raises some important questions about how it is conceptualised. Additionally, support is given for the manager to be seen as the primary organisational counterpart to the employee in future theoretical and practical work. The research also argues to extend current notions of time within the psychological contract as this seems to be the most divergent and combustible issue across the generations in terms of how the workplace is perceived. A number of practical implications also transpire from the study and the collaborative foundation was highly successful. It is anticipated that this research will make a meaningful contribution to both the theory and practice of the employment relationship with particular regard to graduates entering the public sector.
Resumo:
Particulate pollution has been widely recognised as an important risk factor to human health. In addition to increases in respiratory and cardiovascular morbidity associated with exposure to particulate matter (PM), WHO estimates that urban PM causes 0.8 million premature deaths globally and that 1.5 million people die prematurely from exposure to indoor smoke generated from the combustion of solid fuels. Despite the availability of a huge body of research, the underlying toxicological mechanisms by which particles induce adverse health effects are not yet entirely understood. Oxidative stress caused by generation of free radicals and related reactive oxygen species (ROS) at the sites of deposition has been proposed as a mechanism for many of the adverse health outcomes associated with exposure to PM. In addition to particle-induced generation of ROS in lung tissue cells, several recent studies have shown that particles may also contain ROS. As such, they present a direct cause of oxidative stress and related adverse health effects. Cellular responses to oxidative stress have been widely investigated using various cell exposure assays. However, for a rapid screening of the oxidative potential of PM, less time-consuming and less expensive, cell-free assays are needed. The main aim of this research project was to investigate the application of a novel profluorescent nitroxide probe, synthesised at QUT, as a rapid screening assay in assessing the oxidative potential of PM. Considering that this was the first time that a profluorescent nitroxide probe was applied in investigating the oxidative stress potential of PM, the proof of concept regarding the detection of PM–derived ROS by using such probes needed to be demonstrated and a sampling methodology needed to be developed. Sampling through an impinger containing profluorescent nitroxide solution was chosen as a means of particle collection as it allowed particles to react with the profluorescent nitroxide probe during sampling, avoiding in that way any possible chemical changes resulting from delays between the sampling and the analysis of the PM. Among several profluorescent nitroxide probes available at QUT, bis(phenylethynyl)anthracene-nitroxide (BPEAnit) was found to be the most suitable probe, mainly due to relatively long excitation and emission wavelengths (λex= 430 nm; λem= 485 and 513 nm). These wavelengths are long enough to avoid overlap with the background fluorescence coming from light absorbing compounds which may be present in PM (e.g. polycyclic aromatic hydrocarbons and their derivatives). Given that combustion, in general, is one of the major sources of ambient PM, this project aimed at getting an insight into the oxidative stress potential of combustion-generated PM, namely cigarette smoke, diesel exhaust and wood smoke PM. During the course of this research project, it was demonstrated that the BPEAnit probe based assay is sufficiently sensitive and robust enough to be applied as a rapid screening test for PM-derived ROS detection. Considering that for all three aerosol sources (i.e. cigarette smoke, diesel exhaust and wood smoke) the same assay was applied, the results presented in this thesis allow direct comparison of the oxidative potential measured for all three sources of PM. In summary, it was found that there was a substantial difference between the amounts of ROS per unit of PM mass (ROS concentration) for particles emitted by different combustion sources. For example, particles from cigarette smoke were found to have up to 80 times less ROS per unit of mass than particles produced during logwood combustion. For both diesel and wood combustion it has been demonstrated that the type of fuel significantly affects the oxidative potential of the particles emitted. Similarly, the operating conditions of the combustion source were also found to affect the oxidative potential of particulate emissions. Moreover, this project has demonstrated a strong link between semivolatile (i.e. organic) species and ROS and therefore, clearly highlights the importance of semivolatile species in particle-induced toxicity.
Resumo:
The purpose of this article is to examine how a consumer’s weight control beliefs (WCB), a female advertising model’s body size (slim or large) and product type influence consumer evaluations and consumer body perceptions. The study uses an experiment of 371 consumers. The design of the experiment was a 2 (weight control belief: internal, external) X 2 (model size: larger sized, slim) X 2 (product type: weight controlling, non-weight controlling) between-participants factorial design. Results reveal two key contributions. First, larger sized models result in consumers feeling less pressure from society to be thin, viewing their actual shape as slimmer relative to viewing a slim model and wanting a thinner ideal body shape. Slim models result in the opposite effects. Second this research reveals a boundary condition for the extent to which endorser–product congruency theory can be generalized to endorsers of a larger body size. Results indicate that consumer WCB may be a useful variable to consider when marketers consider the use of larger models in advertising.
Resumo:
Intrusive thoughts about food may play a role in unhealthy eating behaviours. Food-related thoughts that capture attention can lead to craving and further intrusive thoughts (Kavanagh, Andrade, & May, 2005). We tested whether diverting attention to mental images or bodily sensations would reduce the incidence of intrusive thoughts about snack foods. In two experiments, participants reported their thoughts in response to probes during three 10 min periods. In the Baseline and Post-task period, participants were asked to let their mind wander. In the middle, Experimental, period, participants followed mind wandering (Control), thought diversion, or Thought Suppression instructions. Self-directed or Guided Imagery, Mindfulness-based Body Scanning, and Thought Suppression all reduced the proportion of thoughts about food, compared to Baseline. Following Body Scanning and Thought Suppression, food thoughts returned to Baseline frequencies Post-task, rather than rebounding. There were no effects of the interventions upon craving, although overall, craving and thought frequency were correlated. Thought control tasks may help people to ignore thoughts about food and thereby reduce their temptation to snack.
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This study examined whether the conspicuity of road workers at night can be enhanced by distributing retroreflective strips across the body to present a pattern of biological motion (biomotion). Twenty visually normal drivers (mean age = 40.3 years) participated in an experiment conducted at two open-road work sites (one suburban and one freeway) at night-time. At each site, four road workers walked in place wearing a standard road worker night vest either (a) alone, (b) with additional retroreflective strips on thighs, (c) with additional retroreflective strips on ankles and knees, or (d) with additional retroreflective strips on eight moveable joints (full biomotion). Participants, seated in stationary vehicles at three different distances (80 m, 160 m, 240 m), rated the relative conspicuity of the four road workers. Road worker conspicuity was maximized by the full biomotion configuration at all distances and at both sites. The addition of ankle and knee markings also provided significant benefits relative to the standard vest alone. The effects of clothing configuration were more evident at the freeway site and at shorter distances. Overall, the full biomotion configuration was ranked to be most conspicuous and the vest least conspicuous. These data provide the first evidence that biomotion effectively enhances conspicuity of road workers at open-road work sites.