Poisson, Poisson-gamma and zero-inflated regression models of motor vehicle crashes: balancing statistical fit and theory

There has been considerable research conducted over the last 20 years focused on predicting motor vehicle crashes on transportation facilities. The range of statistical models commonly applied includes binomial, Poisson, Poisson-gamma (or negative binomial), zero-inflated Poisson and negative binomial models (ZIP and ZINB), and multinomial probability models. Given the range of possible modeling approaches and the host of assumptions with each modeling approach, making an intelligent choice for modeling motor vehicle crash data is difficult. There is little discussion in the literature comparing different statistical modeling approaches, identifying which statistical models are most appropriate for modeling crash data, and providing a strong justification from basic crash principles. In the recent literature, it has been suggested that the motor vehicle crash process can successfully be modeled by assuming a dual-state data-generating process, which implies that entities (e.g., intersections, road segments, pedestrian crossings, etc.) exist in one of two states—perfectly safe and unsafe. As a result, the ZIP and ZINB are two models that have been applied to account for the preponderance of “excess” zeros frequently observed in crash count data. The objective of this study is to provide defensible guidance on how to appropriate model crash data. We first examine the motor vehicle crash process using theoretical principles and a basic understanding of the crash process. It is shown that the fundamental crash process follows a Bernoulli trial with unequal probability of independent events, also known as Poisson trials. We examine the evolution of statistical models as they apply to the motor vehicle crash process, and indicate how well they statistically approximate the crash process. We also present the theory behind dual-state process count models, and note why they have become popular for modeling crash data. A simulation experiment is then conducted to demonstrate how crash data give rise to “excess” zeros frequently observed in crash data. It is shown that the Poisson and other mixed probabilistic structures are approximations assumed for modeling the motor vehicle crash process. Furthermore, it is demonstrated that under certain (fairly common) circumstances excess zeros are observed—and that these circumstances arise from low exposure and/or inappropriate selection of time/space scales and not an underlying dual state process. In conclusion, carefully selecting the time/space scales for analysis, including an improved set of explanatory variables and/or unobserved heterogeneity effects in count regression models, or applying small-area statistical methods (observations with low exposure) represent the most defensible modeling approaches for datasets with a preponderance of zeros

Faculty and students’ awareness and challenges of e-learning in a college of education

This study explored the use of e-learning by student teachers and faculty members at the Paro College of Education, Royal University of Bhutan. It provides an overview of the current status of e-learning at the College including the challenges faced by both faculty members and students teachers, and the influence of ICT resources on the use of e-learning by the lecturers and student teachers. The results indicated that there exist challenges in exercising e-learning at the College for teaching and learning. The data indicated that the Internet connection is slow and revealed that most of the lecturers have average computer competency. This study strongly recommends that the College develops a strategic plan for ICT infrastructure and resources that includes policy and guidelines for use. This study also suggests that lecturers and student teachers use freely available e-learning management software.

Is a mango just a mango? Testing within-fruit oviposition site choice and larval performance of a highly polyphagous fruit fly

For fruit flies, fully ripe fruit is preferred for adult oviposition and is superior for offspring performance over unripe or ripening fruit. Because not all parts of a single fruit ripen simultaneously, the opportunity exists for adult fruit flies to selectively choose riper parts of a fruit for oviposition and such selection, if it occurs, could positively influence offspring performance. Such fine scale host variation is rarely considered in fruit fly ecology, however, especially for polyphagous species which are, by definition, considered to be generalist host users. Here we study the adult oviposition preference/larval performance relationship of the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), a highly polyphagous pest species, at the “within-fruit” level to see if such a host use pattern occurs. We recorded the number of oviposition attempts that female flies made into three fruit portions (top, middle and bottom), and larval behavior and development within different fruit portions for ripening (color change) and fully-ripe mango, Mangifera indica L. (Anacardiaceae). Results indicate that female B. dorsalis do not oviposit uniformly across a mango fruit, but lay most often in the top (i.e., stalk end) of fruit and least in the bottom portion, regardless of ripening stage. There was no evidence of larval feeding site preference or performance (development time, pupal weight, percent pupation) being influenced by fruit portion, within or across the fruit ripening stages. There was, however, a very significant effect on adult emergence rate from pupae, with adult emergence rate from pupae from the bottom of ripening mango being approximately only 50% of the adult emergence rate from the top of ripening fruit, or from both the top and bottom of fully-ripe fruit. Differences in mechanical (firmness) and chemical (total soluble solids, titratable acidity, total non-structural carbohydrates) traits between different fruit portions were correlated with adult fruit utilisation. Our results support a positive adult preference/offspring performance relationship at within-fruit level for B. dorsalis. The fine level of host discrimination exhibited by B. dorsalis is at odds with the general perception that, as a polyphagous herbivore, the fly should show very little discrimination in its host use behavior.

A review of rationale for allocating costs and payments in producing and supplying public sector information PART A of 2 Parts – Chapters 1, 2 and 3) 13 March 2011 version

This work reviews the rationale and processes for raising revenue and allocating funds to perform information intensive activities that are pertinent to the work of democratic government. ‘Government of the people, by the people, for the people’ expresses an idea that democratic government has no higher authority than the people who agree to be bound by its rules. Democracy depends on continually learning how to develop understandings and agreements that can sustain voting majorities on which democratic law making and collective action depends. The objective expressed in constitutional terms is to deliver ‘peace, order and good government’. Meeting this objective requires a collective intellectual authority that can understand what is possible; and a collective moral authority to understand what ought to happen in practice. Facts of life determine that a society needs to retain its collective competence despite a continual turnover of its membership as people die but life goes on. Retaining this ‘collective competence’ in matters of self-government depends on each new generation: • acquiring a collective knowledge of how to produce goods and services needed to sustain a society and its capacity for self-government; • Learning how to defend society diplomatically and militarily in relation to external forces to prevent overthrow of its self-governing capacity; and • Learning how to defend society against divisive internal forces to preserve the authority of representative legislatures, allow peaceful dispute resolution and maintain social cohesion.

Vulnerable and invisible : depictions of trafficking victims in public awareness campaigns

Public concern about the crime of human trafficking has dramatically risen over the last two decades. . This concern and panic has both spawned and been fuelled by an array of public awareness campaigns that aim to educate the public about this crime. Campaigns such as the Blue Blindfold Campaign in the UK, the UN-driven Blue Heart Campaign, and the worldwide Body Shop campaign have contributed to the public’s awareness and, to an extent, understanding of the phenomenon of human trafficking. This research explores these and other government and non-government campaigns aimed at raising public awareness of human trafficking. It questions the rationale, call to action and impact of these efforts, and analyses the depiction of trafficking victims in these campaigns. In particular, this research argues that some of these campaigns perpetuate an understanding of a hierarchy of victimisation of trafficking. A public focus on sex trafficking often results in the conflation of prostitution and trafficking, and renders invisible the male and female victims of trafficking for other forms of labour.

Negative change and job outcomes : the impact of subjective fit in public sector health care organization

There is an ongoing level of organizational-wide change (such as empowerment and downsizing) occurring within the Australian health care sector. However, there is a paucity of empirical evidence on how public and nonprofit sector nurses cope with these organizational-wide change initiatives and their consequences on individual and work outcomes. This will be the primary aim of the current paper. To this end, a path model is developed base on an integration of existing theoretical perspectives on occupational stress, change management, and person-organizational fit. Data were collected from 252 public and not-for-profit sector nurses. The path analysis suggests that public and nonprofit nurses experience positive and negative change initiatives. Negative change initiatives resulted in an increase in the level of administrative-related stressors. Nurses with more congruent values report less experience with administrative stressors. As nurses experienced more administrative stressors, they tend to report more job dissatisfaction. Nurses whose values were more congruent during organizational change reported higher level of psychological wellbeing. Nurses who were had higher level of psychological wellbeing were found to have higher job satisfaction, which subsequently led to a higher level of organizational commitment.

Kaleidoscopes and contradictions : the legitimacy of social media for public relations

If the current discourses of progress are to be believed, the new or social media promise a kaleidoscope of opportunity for connecting and informing citizens. This is by allegedly revitalizing the fading legitimacy and practice of institutions and providing an agent for social interaction. However, as social media adoption has increased, it has revealed a wealth of contradictions both of its own making and reproduction of past action. This has created a crisis for traditional media as well as for public relations. For example, social media such as WikiLeaks have bypassed official channels about government information. In other cases, social media such as Facebook and Twitter informed BBC coverage of the Rio Olympics. Although old media are unlikely to go away, social media have had an impact with several large familybased media companies collapsing or being reintegrated into the new paradigm. To use Walter Lippman’s analogy of the phantom public, the social media contradictorily serve to both disparate the phantom in part and reinforce it...

Automated speed enforcement in Australia : recent examples of the influence of public opinion on program sustainability

In Australia, speeding remains a substantial contributor to road trauma. The National Road Safety Strategy (2011-2020) highlighted the need to harness community support for current and future speed management strategies. Australia is known for intensive speed camera programs which are both automated and manual, employing covert and overt methods. Recent developments in the area of automated speed enforcement in Australia help to illustrate the important link between community attitudes to speed enforcement and subsequent speed camera policy developments. A perceived lack of community confidence in camera programs prompted reviews in New South Wales and Victoria in 2011 by the jurisdictional Auditor-General. This paper explores automated speed camera enforcement in Australia with particular reference to the findings of these two reports as they relate to the level of public support for and community attitudes towards automated speed enforcement. It also provides comment on the evolving nature of automated speed enforcement according to previously identified controversies and dilemmas associated with speed camera programs.

Design of open source framework for traffic and travel simulation

For the evaluation, design, and planning of traffic facilities and measures, traffic simulation packages are the de facto tools for consultants, policy makers, and researchers. However, the available commercial simulation packages do not always offer the desired work flow and flexibility for academic research. In many cases, researchers resort to designing and building their own dedicated models, without an intrinsic incentive (or the practical means) to make the results available in the public domain. To make matters worse, a substantial part of these efforts pertains to rebuilding basic functionality and, in many respects, reinventing the wheel. This problem not only affects the research community but adversely affects the entire traffic simulation community and frustrates the development of traffic simulation in general. For this problem to be addressed, this paper describes an open source approach, OpenTraffic, which is being developed as a collaborative effort between the Queensland University of Technology, Australia; the National Institute of Informatics, Tokyo; and the Technical University of Delft, the Netherlands. The OpenTraffic simulation framework enables academies from geographic areas and disciplines within the traffic domain to work together and contribute to a specific topic of interest, ranging from travel choice behavior to car following, and from response to intelligent transportation systems to activity planning. The modular approach enables users of the software to focus on their area of interest, whereas other functional modules can be regarded as black boxes. Specific attention is paid to a standardization of data inputs and outputs for traffic simulations. Such standardization will allow the sharing of data with many existing commercial simulation packages.

Australian and New Zealand nurses’ perceptions of procedural sedation and analgesia in the cardiac catheterisation laboratory : a qualitative study

Background: Australian and New Zealand College of Anaesthetists’ guidelines for procedural sedation and analgesia (PSA) are intended to apply across all clinical settings. As nurses are frequently responsible for patient care during PSA in the cardiac catheterisation laboratory (CCL), their perspectives can provide insight into the effectiveness of these guidelines within this particular setting. Methods: A cross-sectional sampling design was used to recruit nurses from urban, regional, public and private CCLs across Australia and New Zealand. Semi-structured interviews were conducted, digitally recorded and transcribed. Data were analysed using thematic analysis. Findings: Twenty-three nurses from 16 CCLs across four states in Australia and New Zealand participated. Most held senior positions (managers=14; educators=5) and CCL experience ranged from 4 to 26 years (mean 11). Participants were concerned about the legitimacy of their practice as they administered PSA outside of guideline recommendations and deemed present education and training as deficient. Participants noted also that guideline recommendations were sometimes not adhered to as it was difficult to balance the increasingly complex PSA requirements of their case-mix with limited access to anaesthetists while trying not to delay procedures. Conclusion: Findings suggest that application of current PSA guidelines may be impractical for CCL nurses and, as a consequence, they are often not followed. Participants were concerned about risks to patient safety as they felt education and training was not commensurable with practice requirements. The findings suggest existing guidelines should be reviewed or new guidelines developed which address nursing practice, education and competency standards for PSA in the CCL

Citizenship, community, public space and the marginalisation of children and young people

Throughout Australia (and in comparable urban contexts around the world) public spaces may be said to be under attack by developers and also attempts by civic authorities to regulate, restrict, rebrand and reframe them. A consequence of the increasingly security driven, privatised and surveilled nature of public space is the exclusion and displacement of those considered flawed and unwelcome in the ‘spectacular’ consumption spaces of many major urban centres. In the name of urban regeneration, processes of securitisation, ‘gentrification’ and creative cities discourses can refashion public space as sites of selective inclusion and exclusion. In this context of monitoring and control procedures, children and young people’s use of space in parks, neighbourhoods, shopping malls and streets is often viewed as a threat to the social order, requiring various forms of punitive and/or remedial action. This paper discusses developments in the surveillance, governance and control of public space used by children and young people in particular and the capacity for their displacement and marginality, diminishing their sense of place and belonging, and right to public space as an expression of their civil, political and social citizenship(s).