433 resultados para DIRECTED PERCOLATION
Resumo:
Small animal fracture models have gained increasing interest in fracture healing studies. To achieve standardized and defined study conditions, various variables must be carefully controlled when designing fracture healing experiments in mice or rats. The strain, age and sex of the animals may influence the process of fracture healing. Furthermore, the choice of the fracture fixation technique depends on the questions addressed, whereby intra- and extramedullary implants as well as open and closed surgical approaches may be considered. During the last few years, a variety of different, highly sophisticated implants for fracture fixation in small animals have been developed. Rigid fixation with locking plates or external fixators results in predominantly intramembranous healing in both mice and rats. Locking plates, external fixators, intramedullary screws, the locking nail and the pin-clip device allow different degrees of stability resulting in various amounts of endochondral and intramembranous healing. The use of common pins that do not provide rotational and axial stability during fracture stabilization should be discouraged in the future. Analyses should include at least biomechanical and histological evaluations, even if the focus of the study is directed towards the elucidation of molecular mechanisms of fracture healing using the largely available spectrum of antibodies and gene-targeted animals to study molecular mechanisms of fracture healing. This review discusses distinct requirements for the experimental setups as well as the advantages and pitfalls of the different fixation techniques in rats and mice.
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Research has shown that people with a mental illness are an at-risk group for sexually transmitted infections. A programme for preventing risk behaviours for sexually transmitted infections among people with psychiatric disorder was designed and implemented by mental health occupational therapists. This programme used an interactive didactic approach to provide education and awareness of sexual health issues to acute psychiatric inpatients. Twenty-four participants completed a sexual health questionnaire, which was designed for this study, both before and after attending the programme. They had a higher than expected knowledge of sexually transmitted infections and safe sex practices at pre-test. The education programme resulted in a statistically significant but modest increase in sexual health knowledge. These findings indicate that there are benefits in providing sexual health education to clients with a mental illness. Further programme development should be directed towards sexual health decision-making and behaviour change.
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Motivation is a major driver of project performance. Despite team member ability to deliver successful project outcomes if they are not positively motivated to pursue joint project goals, then performance will be constrained. One approach to improving the motivation of project organizations is by offering a financial reward for the achievement of set performance standards above a minimum required level. However, little investigation has been undertaken into the features of successful incentive systems as a part of an overall delivery strategy. With input from organizational management literature, and drawing on the literature covering psychological and economic theories of motivation, this paper presents an integrated framework that can be used by project organizations to assess the impact of financial reward systems on motivation in construction projects. The integrated framework offers four motivation indicators which reflect key theoretical concepts across both psychological and economic disciplines. The indicators are: (1) Goal Commitment, (2) Distributive Justice, (3) Procedural Justice, and (4) Reciprocity. The paper also interprets the integrated framework against the results of a successful Australian social infrastructure project case study and identifies key learning’s for project organizations to consider when designing financial reward systems. Case study results suggest that motivation directed towards the achievement of incentive goals is influenced not only by the value placed on the financial reward for commercial benefit, but also driven by the strength of the project initiatives that encourage just and fair dealings, supporting the establishment of trust and positive reciprocal behavior across a project team. The strength of the project relationships was found to be influenced by how attractive the achievement of the goal is to the incentive recipient and how likely they were to push for the achievement of the goal. Interestingly, findings also suggested that contractor motivation is also influenced by the fairness of the performance measurement process and their perception of the trustworthiness and transparency of their client. These findings provide the basis for future research on the impact of financial reward systems on motivation in construction projects. It is anticipated that such research will shed new light on this complex topic and further define how reward systems should be designed to promote project team motivation. Due to the unique nature of construction projects with high levels of task complexity and interdependence, results are expected to vary in comparison to previous studies based on individuals or single-entity organizations.
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How can Australian library and information science (LIS) education produce, in a sustainable manner, the diverse supply of graduates with the appropriate attributes to develop and maintain high quality professional practice in the rapidly changing 21st century? This report presents the key findings of a project that has examined this question through research into future directions for LIS education in Australia. Titled Re-conceptualising and re-positioning Australian library and information science education for the twenty-first century, the purpose of the project was to establish a consolidated and holistic picture of the Australian LIS profession, and identify how its future education and training can be mediated in a cohesive and sustainable manner. The project was undertaken with a team of 12 university and vocational LIS educators from 11 institutions around Australia between November 2009 and December 2010. Collectively, these eleven institutions represented the broad spectrum and diversity of LIS education in Australia, and enabled the project to examine education for the information profession in a holistic and synergistic manner. Participating institutions in the project included Queensland University of Technology (Project Leader), Charles Sturt University, Curtin University of Technology, Edith Cowan University, Monash University, RMIT University, University of Canberra, University of South Australia, University of Tasmania, University of Technology Sydney and Victoria University. The inception and need for the project was motivated by a range of factors. From a broad perspective several of these factors relate to concerns raised at national and international levels regarding problems with education for LIS. In addition, the motivation and need for the project also related to some unique challenges that LIS education faces in the Australian tertiary education landscape. Over recent years a range of responses to explore the various issues confronting LIS education in Australia have emerged at local and national levels however this project represented the first significant investment of funding for national research in this area. In this way, the inception of the project offered a unique opportunity and powerful mechanism through which to bring together key stakeholders and inspire discourse concerning future education for the profession. Therefore as the first national project of its kind, its intent has been to provide foundation research that will inform and guide future directions for LIS education and training in Australia. The primary objective of the project was to develop a Framework for the Education of the Information Professions in Australia. The purpose of this framework was to provide evidence based strategic recommendations that would guide Australia’s future education for the information professions. Recognising the three major and equal players in the education process the project was framed around three areas of consideration: LIS students, the LIS workforce and LIS educators. Each area of consideration aligned to a research substudy in the project. The three research substudies were titled Student Considerations, Workforce Planning Considerations and Tertiary Education Considerations. The Students substudy provided a profile of LIS students and an analysis of their choices, experiences and expectations in regard to LIS education and their graduate destinations. The Workforce substudy provided an overview and analysis of the nature of the current LIS workforce, including a focus on employer expectations and employment opportunities and comment on the core and elective skill, knowledge and attitudes of current and future LIS professionals. Finally the Tertiary Education substudy provided a profile of LIS educators and an analysis of their characteristics and experiences including the key issues and challenges. In addition it also explored current national and international trends and priorities impacting on LIS education. The project utilised a Community Based Participatory Research (CBPR) approach. This approach involves all members of the community in all aspects of the project. It recognised the unique strengths and perspectives that community members bring to the process. For this project ‘community’ comprised of all individuals who have a role in, or a vested interest in, LIS education and included LIS educators, professionals, employers, students and professional associations. Individuals from these sub-groups were invited to participate in a range of aspects of the project from design through to implementation and evaluation. A range of research methodologies were used to consider the many different perspectives of LIS education, including employers and recruiters, professional associations, students, graduates and LIS teaching staff. Data collection involved a mixed method approach of questionnaires, focus groups, semi-structured interviews and environmental scans. An array of approaches was selected to ensure that broadest possible access to different facets of the information profession would be achieved. The main findings and observations from each substudy have highlighted a range of challenges for LIS education that need to be addressed. These findings and observations have grounded the development of the Framework for the Education of the Information Professions in Australia. The framework presents eleven recommendations to progress the national approach to LIS education and guide Australia’s future education for the information professions. The framework will be used by the LIS profession, most notably its educators, as strategic directions for the future of LIS education in Australia. Framework for the Education of the Information Professions in Australia: Recommendation 1: It is recommended that a broader and more inclusive vocabulary be adopted that both recognises and celebrates the expanding landscape of the field, for example ‘information profession’, ‘information sector’, ‘information discipline’ and ‘information education’. Recommendation 2: It is recommended that a self-directed body composed of information educators be established to promote, support and lead excellence in teaching and research within the information discipline. Recommendation 3: It is recommended that Australia’s information discipline continue to develop excellence in information research that will raise the discipline’s profile and contribute to its prominence within the national and international arena. Recommendation 4: It is recommended that further research examining the nature and context of Australia’s information education programs be undertaken to ensure a sustainable and relevant future for the discipline. Recommendation 5: It is recommended that further research examining the pathways and qualifications available for entry into the Australian information sector be undertaken to ensure relevance, attractiveness, accessibility and transparency. Recommendation 6: It is recommended that strategies are developed and implemented to ensure the sustainability of the workforce of information educators. Recommendation 7: It is recommended that a national approach to promoting and marketing the information profession and thereby attracting more students to the field is developed. Recommendation 8: It is recommended that Australia’s information discipline continues to support a culture of quality teaching and learning, especially given the need to accommodate a focus on the broader information landscape and more flexible delivery options. Recommendation 9: It is recommended that strategies are developed that will support and encourage collaboration between information education within the higher education and VET sectors. Recommendation 10: It is recommended that strategies and forums are developed that will support the information sector working together to conceptualise and articulate their professional identity and educational needs. Recommendation 11: It is recommended that a research agenda be established that will identify and prioritise areas in which further development or work is needed to continue advancing information education in Australia. The key findings from this project confirm that a number of pressing issues are confronting LIS education in Australia. Left unaddressed these issues will have significant implications for the future of LIS education as well as the broader LIS profession. Consequently creating a sustainable and cohesive future can only be realised through cooperation and collaboration among all stakeholders including those with the capacity to enact radical change in university and vocational institutions. Indeed the impending adoption and implementation of the project’s recommendations will fundamentally determine whether Australian LIS education is assured both for the present day and into the future.
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The research objectives of this thesis were to contribute to Bayesian statistical methodology by contributing to risk assessment statistical methodology, and to spatial and spatio-temporal methodology, by modelling error structures using complex hierarchical models. Specifically, I hoped to consider two applied areas, and use these applications as a springboard for developing new statistical methods as well as undertaking analyses which might give answers to particular applied questions. Thus, this thesis considers a series of models, firstly in the context of risk assessments for recycled water, and secondly in the context of water usage by crops. The research objective was to model error structures using hierarchical models in two problems, namely risk assessment analyses for wastewater, and secondly, in a four dimensional dataset, assessing differences between cropping systems over time and over three spatial dimensions. The aim was to use the simplicity and insight afforded by Bayesian networks to develop appropriate models for risk scenarios, and again to use Bayesian hierarchical models to explore the necessarily complex modelling of four dimensional agricultural data. The specific objectives of the research were to develop a method for the calculation of credible intervals for the point estimates of Bayesian networks; to develop a model structure to incorporate all the experimental uncertainty associated with various constants thereby allowing the calculation of more credible credible intervals for a risk assessment; to model a single day’s data from the agricultural dataset which satisfactorily captured the complexities of the data; to build a model for several days’ data, in order to consider how the full data might be modelled; and finally to build a model for the full four dimensional dataset and to consider the timevarying nature of the contrast of interest, having satisfactorily accounted for possible spatial and temporal autocorrelations. This work forms five papers, two of which have been published, with two submitted, and the final paper still in draft. The first two objectives were met by recasting the risk assessments as directed, acyclic graphs (DAGs). In the first case, we elicited uncertainty for the conditional probabilities needed by the Bayesian net, incorporated these into a corresponding DAG, and used Markov chain Monte Carlo (MCMC) to find credible intervals, for all the scenarios and outcomes of interest. In the second case, we incorporated the experimental data underlying the risk assessment constants into the DAG, and also treated some of that data as needing to be modelled as an ‘errors-invariables’ problem [Fuller, 1987]. This illustrated a simple method for the incorporation of experimental error into risk assessments. In considering one day of the three-dimensional agricultural data, it became clear that geostatistical models or conditional autoregressive (CAR) models over the three dimensions were not the best way to approach the data. Instead CAR models are used with neighbours only in the same depth layer. This gave flexibility to the model, allowing both the spatially structured and non-structured variances to differ at all depths. We call this model the CAR layered model. Given the experimental design, the fixed part of the model could have been modelled as a set of means by treatment and by depth, but doing so allows little insight into how the treatment effects vary with depth. Hence, a number of essentially non-parametric approaches were taken to see the effects of depth on treatment, with the model of choice incorporating an errors-in-variables approach for depth in addition to a non-parametric smooth. The statistical contribution here was the introduction of the CAR layered model, the applied contribution the analysis of moisture over depth and estimation of the contrast of interest together with its credible intervals. These models were fitted using WinBUGS [Lunn et al., 2000]. The work in the fifth paper deals with the fact that with large datasets, the use of WinBUGS becomes more problematic because of its highly correlated term by term updating. In this work, we introduce a Gibbs sampler with block updating for the CAR layered model. The Gibbs sampler was implemented by Chris Strickland using pyMCMC [Strickland, 2010]. This framework is then used to consider five days data, and we show that moisture in the soil for all the various treatments reaches levels particular to each treatment at a depth of 200 cm and thereafter stays constant, albeit with increasing variances with depth. In an analysis across three spatial dimensions and across time, there are many interactions of time and the spatial dimensions to be considered. Hence, we chose to use a daily model and to repeat the analysis at all time points, effectively creating an interaction model of time by the daily model. Such an approach allows great flexibility. However, this approach does not allow insight into the way in which the parameter of interest varies over time. Hence, a two-stage approach was also used, with estimates from the first-stage being analysed as a set of time series. We see this spatio-temporal interaction model as being a useful approach to data measured across three spatial dimensions and time, since it does not assume additivity of the random spatial or temporal effects.
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Objective: Older driver research has mostly focused on identifying that small proportion of older drivers who are unsafe. Little is known about how normal cognitive changes in aging affect driving in the wider population of adults who drive regularly. We evaluated the association of cognitive function and age, with driving errors. Method: A sample of 266 drivers aged 70 to 88 years were assessed on abilities that decline in normal aging (visual attention, processing speed, inhibition, reaction time, task switching) and the UFOV® which is a validated screening instrument for older drivers. Participants completed an on-road driving test. Generalized linear models were used to estimate the associations of cognitive factor with specific driving errors and number of errors in self-directed and instructor navigated conditions. Results: All errors types increased with chronological age. Reaction time was not associated with driving errors in multivariate analyses. A cognitive factor measuring Speeded Selective Attention and Switching was uniquely associated with the most errors types. The UFOV predicted blindspot errors and errors on dual carriageways. After adjusting for age, education and gender the cognitive factors explained 7% of variance in the total number of errors in the instructor navigated condition and 4% of variance in the self-navigated condition. Conclusion: We conclude that among older drivers errors increase with age and are associated with speeded selective attention particularly when that requires attending to the stimuli in the periphery of the visual field, task switching, errors inhibiting responses and visual discrimination. These abilities should be the target of cognitive training.
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In recent times considerable research attention has been directed to understanding dark networks, especially criminal and terrorist networks. Dark networks are those in which member motivations are self rather than public interested, achievements come at the cost of other individuals, groups or societies and, in addition, their activities are both ‘covert and illegal’ (Raab & Milward, 2003: 415). This ‘darkness’ has implications for the way in which these networks are structured, the strategies adopted and their recruitment methods. Such entities exhibit distinctive operating characteristics including most notably the tension between creating an efficient network structure while retaining the ability to hide from public view while avoiding catastrophic collapse should one member cooperate with authorities (Bouchard 2007). While theoretical emphasis has been on criminal and terrorist networks, recent work has demonstrated that corrupt police networks exhibit some distinctive characteristics. In particular, these entities operate within the shadows of a host organisation - the Police Force and distort the functioning of the ‘Thin Blue Line’ as the interface between the law abiding citizenry and the criminal society. Drawing on data derived from the Queensland Fitzgerald Commission of Enquiry into Police Misconduct and related documents, this paper examines the motivations, structural properties and operational practices of corrupt police networks and compares and contrasts these with other dark networks with ‘bright’ public service networks. The paper confirms the structural differences between dark corrupt police networks and bright networks and suggests. However, structural embeddedness alone is found to be an insufficient theoretical explanation for member involvement in networks and that a set of elements combine to impact decision-making. Although offering important insights into network participation, the paper’s findings are especially pertinent in identifying additional points of intervention for police corruption networks.
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In their 2010 study drawing on 500 empirical philanthropy studies, Bekkers and Wiepking identified eight consistently significant giving mechanisms. The pilot study reported here extends what is known about one mechanism, values, as a giving driver, in particular considering how national cultural values apply to giving. Personal values are not formed in a vacuum. They are influenced by the wider culture and society: thus values have a socio-cultural dimension. Accordingly, this pilot research draws on media theory and cultural studies work on national ethos to explore how these national cultural values interact with giving. A directed qualitative content analysis has been undertaken to compare US and Australian print media coverage about philanthropy. The two nations share an Anglo–Saxon orientation but differ significantly in national character and philanthropic activity. This study posits that a nation's media coverage about giving will reflect its national cultural ethos. This coverage can also shape personal values, thus implications exist for theory about the antecedents of personal giving values. Wider national values may drive or stifle giving, so this wider view of values as a driver has implications also for philanthropy promotion and fundraising.
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Background: Considerable attention is currently being directed towards both active ageing and the revising of standards for disability services within Australia and internationally. Yet, to date, no consideration appears to have been given to ways to promote active ageing among older adults with intellectual disabilities. Methods: Semi-structured interviews were conducted with 16 Australian professional direct-care support staff (service providers) about their perceptions of ageing among older adults with lifelong intellectual disabilities and what active ageing might entail for an individual from this population who is currently under their care, in both the present and future. Data were analysed against the six core World Health Organization active ageing outcomes for people with intellectual disabilities. Results: Service providers appeared to be strongly focused on encouraging active ageing among their clients. However, their perceptions of the individual characteristics, circumstances and experiences of older adults with intellectual disabilities for whom they care suggest that active ageing principles need to be applied to this group in a way that considers both their individual and diverse needs, particularly with respect to them transitioning from day services, employment or voluntary work to reduced activity, and finally to aged care facilities. The appropriateness of this group being placed in nursing homes in old age was also questioned. Conclusion: Direct-care staff of older adults with intellectual disabilities have a vital role to play in encouraging and facilitating active ageing, as well as informing strategies that need to be implemented to ensure appropriate care for this diverse group as they proceed to old age.
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The Lingodroids are a pair of mobile robots that evolve a language for places and relationships between places (based on distance and direction). Each robot in these studies has its own understanding of the layout of the world, based on its unique experiences and exploration of the environment. Despite having different internal representations of the world, the robots are able to develop a common lexicon for places, and then use simple sentences to explain and understand relationships between places even places that they could not physically experience, such as areas behind closed doors. By learning the language, the robots are able to develop representations for places that are inaccessible to them, and later, when the doors are opened, use those representations to perform goal-directed behavior.
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Bioinformatics involves analyses of biological data such as DNA sequences, microarrays and protein-protein interaction (PPI) networks. Its two main objectives are the identification of genes or proteins and the prediction of their functions. Biological data often contain uncertain and imprecise information. Fuzzy theory provides useful tools to deal with this type of information, hence has played an important role in analyses of biological data. In this thesis, we aim to develop some new fuzzy techniques and apply them on DNA microarrays and PPI networks. We will focus on three problems: (1) clustering of microarrays; (2) identification of disease-associated genes in microarrays; and (3) identification of protein complexes in PPI networks. The first part of the thesis aims to detect, by the fuzzy C-means (FCM) method, clustering structures in DNA microarrays corrupted by noise. Because of the presence of noise, some clustering structures found in random data may not have any biological significance. In this part, we propose to combine the FCM with the empirical mode decomposition (EMD) for clustering microarray data. The purpose of EMD is to reduce, preferably to remove, the effect of noise, resulting in what is known as denoised data. We call this method the fuzzy C-means method with empirical mode decomposition (FCM-EMD). We applied this method on yeast and serum microarrays, and the silhouette values are used for assessment of the quality of clustering. The results indicate that the clustering structures of denoised data are more reasonable, implying that genes have tighter association with their clusters. Furthermore we found that the estimation of the fuzzy parameter m, which is a difficult step, can be avoided to some extent by analysing denoised microarray data. The second part aims to identify disease-associated genes from DNA microarray data which are generated under different conditions, e.g., patients and normal people. We developed a type-2 fuzzy membership (FM) function for identification of diseaseassociated genes. This approach is applied to diabetes and lung cancer data, and a comparison with the original FM test was carried out. Among the ten best-ranked genes of diabetes identified by the type-2 FM test, seven genes have been confirmed as diabetes-associated genes according to gene description information in Gene Bank and the published literature. An additional gene is further identified. Among the ten best-ranked genes identified in lung cancer data, seven are confirmed that they are associated with lung cancer or its treatment. The type-2 FM-d values are significantly different, which makes the identifications more convincing than the original FM test. The third part of the thesis aims to identify protein complexes in large interaction networks. Identification of protein complexes is crucial to understand the principles of cellular organisation and to predict protein functions. In this part, we proposed a novel method which combines the fuzzy clustering method and interaction probability to identify the overlapping and non-overlapping community structures in PPI networks, then to detect protein complexes in these sub-networks. Our method is based on both the fuzzy relation model and the graph model. We applied the method on several PPI networks and compared with a popular protein complex identification method, the clique percolation method. For the same data, we detected more protein complexes. We also applied our method on two social networks. The results showed our method works well for detecting sub-networks and give a reasonable understanding of these communities.
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This paper is directed towards providing an answer to the question, ”Can you control the trajectory of a Lagrangian float?” Being a float that has minimal actuation (only buoyancy control), their horizontal trajectory is dictated through drifting with ocean currents. However, with the appropriate vertical actuation and utilising spatio-temporal variations in water speed and direction, we show here that broad controllabilty results can be met such as waypoint following to keep a float inside of a bay or out of a designated region. This paper extends theory experimen- tally evaluted on horizontally actuated Autonomous Underwater Vehicles (AUVs) for trajectory control utilising ocean forecast models and presents an initial investi- gation into the controllability of these minimally actuated drifting AUVs. Simulated results for offshore coastal and within highly dynamic tidal bays illustrate two tech- niques with the promise for an affirmative answer to the posed question above.
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‘Explosive Revelations’ employs the device of the Hollywood-style explosion to expose the constructed and futile nature of the moving image. Pointless, impotent explosions bloom and fade, punctuating a non-existent narrative – they promise the spectacle of violence but destroy nothing and disappear without a trace. The video itself is sourced from a stock footage supplier that provides users with a selection of explosions that can be inserted into movies by masking out the background. However, the footage is not used as intended, leaving them instead as merely explosions erupting on top of a black background, fizzling out into non-existence. The work was included in the 2008 'Light in Winter' program at Federation Square, Melbourne, directed by Robyn Archer.
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Given significant government attention to, and expenditure on, Indigenous equity in Australia, this article addresses a core problem: the lack of a sound understanding of Indigenous social attitudes and priorities. An account of cultural theory raises the likelihood of difference in outlook between Indigenous and non-Indigenous people, including those making and implementing policy. Yet, years of scholarly research and official statistical collections have overlooked potentially critical aspects of Indigineity. Suggestions of difference emerge from reference to the 2007 Australian Survey of Social Attitudes (AuSSA). If the attitudes recorded a small sample in this instrument manifest in the Indigenous population at large, policy priorities and directions should be reviewed and possibly revised. Despite inherent methodological difficulties, the article calls for targeted social attitude research among Australia's Indigenous peoples so that future policy can be better oriented and calibrated. The national benefits would outweigh the costs via better directed policy making.
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This study examined the effect that temporal order within the entrepreneurial discovery exploitation process has on the outcomes of venture creation. Consistent with sequential theories of discovery-exploitation, the general flow of venture creation was found to be directed from discovery toward exploitation in a random sample of nascent ventures. However, venture creation attempts which specifically follow this sequence derive poor outcomes. Moreover, simultaneous discovery-exploitation was the most prevalent temporal order observed, and venture attempts that proceed in this manner more likely become operational. These findings suggest that venture creation is a multi-scale phenomenon that is at once directional in time, and simultaneously driven by symbiotically coupled discovery and exploitation.