Point-to-point speed enforcement

This report reviews the use of point-to-point speed enforcement internationally in order to provide principles for better practice for its use in Australia and New Zealand. Point-to-point enforcement is a relatively new technological approach to speed enforcement which involves measuring the average speed of vehicles passing a series of cameras, by using automatic number plate recognition (ANPR) and other technologies. The approach has been implemented or trialled in a number of countries including Australia, New Zealand, the United Kingdom, the Netherlands, Austria, Italy, Switzerland and France. The major research activities were undertaken for the preparation of this report included: (1) an extensive review of the international literature; (2) stakeholder consultation with international and domestic organisations. To date, there have been no formal evaluations of point-to- point speed enforcement in Australia or New Zealand.

Teaching about trafficking : opportunities and challenges for critical engagement

When I was first invited to teach a women's studies course called Sex Trafficking in 2002, most of my students had never heard of the issue. Internet and literature searches for "trafficking" mostly turned up references to trafficking in drugs and weapons, not people. When I revised the course for a topical capstone in Criminology, Justice, and Policy Studies in 2006, all of my students had heard about human trafficking, and a handful had already studied it in other classes. The availability of books, films, scholarly articles, and advocacy pieces had all increased exponentially since I first became engaged in the field. This bounty provided a wealth of resources for teaching but also presented a greater challenge when it came to deciding which texts to include. It also added to the inevitable pedagogical angst over what to leave out. I came to know about trafficking by accident, when I was hired as a research assistant at The Protection Project (TPP) in 1999. In my time at TPP I authored a literature review on human trafficking. At that time, my comprehensive database of sources contained fewer than one hundred books and articles, a few UN documents, a handful of films, and some websites from nongovernmental organizations. My review of the literature inevitably reflected the ideological chasm between those who saw trafficking as primarily a labor, migration, and rights issue and those who saw it as primarily a sexual exploitation issue. On the policy end, these ideological orientations created bizarre bedfellows of individuals and organizations that otherwise would have been at odds. The ideological divide has not diminished in the intervening years, and it is important to be aware of and to negotiate this in designing a course on trafficking. As a feminist teacher, I was very aware of the divisions among feminists on the subject of trafficking, and was interested in communicating these differences to students who were not well versed in the varieties of feminist thought. I was also mindful of the difficulties my American students had in engaging with some of the course texts and issues the first time around. For some students, moral judgments about prostitutes were as far as they were able to go in engaging with the course. These students could not find a way in to think about the many issues involved in trafficking. How could I reach them? In this article, I share some of my texts and tactics with others who might find themselves in a position to teach about human trafficking. I include my case for why feminist teachers should teach trafficking, an overview of the debate that divides the field, my rationale for organizing the course the way that I did, issues to consider when designing a course on trafficking, and some suggested readings, films, and web resources.

Routledge handbook of critical criminology

The Routledge Handbook of Critical Criminology is a collection of original essays specifically designed to offer students, faculty, policy makers, and others an in-depth overview of the most up-to-date empirical, theoretical, and political contributions made by critical criminologists around the world. Special attention is devoted to new theoretical directions in the field, such as cultural criminology, masculinities studies, and feminist criminologies. Its diverse essays not only cover the history of critical criminology and cutting edge theories, but also the variety of research methods used by leading scholars in the field and the rich data generated by their rigorous empirical work. In addition, some of the chapters suggest innovative and realistic short- and long-term policy proposals that are typically ignored by mainstream criminology. These progressive strategies address some of the most pressing social problems facing contemporary society today, and that generate much pain and suffering for socially and economically disenfranchised people. The Handbook explores up-to-date empirical, theoretical, and political contributions, and is specifically designed to be a comprehensive resource for undergraduate and post-graduate students, researchers, and policy makers.

An expanded critical incident approach for exploring information use and learning

Critical incidents offer a focus for exploratory research about human experiences, including information use and information literacy learning. This paper describes how critical incidents underpinned research about international students’ use of online information resources at two Australian universities. It outlines the development and application of an expanded critical incident approach (ECIA), explaining how ECIA built upon critical incident technique (CIT) and incorporated information literacy theory. It discusses points of expansion (differences) between CIT and ECIA. While CIT initially proved useful in structuring the research, the pilot study revealed methodological limitations. ECIA allowed more nuanced data analysis and the integration of reflection. The study produced a multifaceted word picture of international students’ experience of using online information resources to learn, and a set of critical findings about their information literacy learning needs. ECIA offers a fresh approach for researching information use, information experience, evidence-based practice, information literacy and informed learning.

In vitro and in vivo studies on protease-activated receptor-2

Protease-activated receptor-2 (PAR2) is a G protein coupled receptor (GPCR) that is activated by proteolytic cleavage of its amino terminal domain by trypsin-like serine proteases. Cleavage of this receptor exposes a neoepitope, termed the tethered ligand (TL), which binds intramolecularly within the receptor to stimulate signal transduction via coupled G proteins. PAR2-mediated signal transduction is also experimentally stimulated by hexapeptides (agonist peptides; APs) that are homologous to the TL sequence. Due to the irreversible nature of PAR2 proteolysis, downstream signal transduction is tightly regulated. Following activation, PAR2 is rapidly uncoupled from downstream signalling by the post-translational modifications phosphorylation and ubiquination which facilitate interactions with â- arrestin. This scaffolding protein couples PAR2 to the internalisation machinery initiating its desensitisation and trafficking through the early and late endosomes followed by receptor degradation. PAR2 is widely expressed in mammalian tissues with key roles for this receptor in cardiovascular, respiratory, nervous and musculoskeletal systems. This receptor has also been linked to pathological states with aberrant expression and signalling noted in several cancers. In prostate cancer, PAR2 signalling induces migration and proliferation of tumour derived cell lines, while elevated receptor expression has been noted in malignant tissues. Importantly, a role for this receptor has also been suggested in prostate cancer bone metastasis as coexpression of PAR2 and a proteolytic activator has been demonstrated by immunohistochemical analysis. Based on these data, the primary focus of this project has been on two aspects of PAR2 biology. The first is characterisation of cellular mechanisms that regulate PAR2 signalling and trafficking. The second aspect is the role of this receptor in prostate cancer bone metastasis. In addition, to permit these studies, it was first necessary to evaluate the specificity of the commercially available anti-PAR2 antibodies SAM11, C17, N19 and H99. The evaluation of the four commercially available antibodies was assessed using four techniques: immunoprecipitation; Western blot analysis; immunofluorescence; and flow cytometry. These approaches demonstrated that three of the antibodies efficiently detect ectopically expressed PAR2 by each of these techniques. A significant finding from this study was that N19 was the only antibody able to specifically detect N-glycosylated endogenous PAR2 by Western blot analysis. This analysis was performed on lysates from prostate cancer derived cell lines and tissue derived from wildtype and PAR2 knockout mice. Importantly, further evaluation demonstrated that this antibody also efficiently detects endogenous PAR2 at the cell surface by flow cytometry. The anti-PAR2 antibody N19 was used to explore the in vitro role of palmitoylation, the post-translational addition of palmitate, in PAR2 signalling, trafficking, cell surface expression and desensitization. Significantly, use of the palmitoylation inhibitor 2-bromopalmitate indicated that palmitate addition is important in trafficking of PAR2 endogenously expressed by prostate cancer cell lines. This was supported by palmitate labelling experiments using two approaches which showed that PAR2 stably expressed by CHO cells is palmitoylated and that palmitoylation occurs on cysteine 361. Another key finding from this study is that palmitoylation is required for optimal PAR2 signalling as Ca2+ flux assays indicated that in response to trypsin agonism, palmitoylation deficient PAR2 is ~9 fold less potent than wildtype receptor with a reduction of about 33% in the maximum signal induced via the mutant receptor. Confocal microscopy, flow cytometry and cell surface biotinylation analyses demonstrated that palmitoylation is required for efficient cell surface expression of PAR2. Importantly, this study also identified that palmitoylation of this receptor within the Golgi apparatus is required for efficient agonist-induced rab11amediated trafficking of PAR2 to the cell surface. Interestingly, palmitoylation is also required for receptor desensitization, as agonist-induced â-arrestin recruitment and receptor degradation were markedly reduced in CHO-PAR2-C361A cells compared with CHO-PAR2 cells. Collectively, these data provide new insights on the life cycle of PAR2 and demonstrate that palmitoylation is critical for efficient signalling, trafficking, cell surface localization and degradation of this receptor. This project also evaluated PAR2 residues involved in ligand docking. Although the extracellular loop (ECL)2 of PAR2 is known to be required for agonist-induced signal transduction, the binding pocket for receptor agonists remains to be determined. In silico homology modelling, based on a crystal structure for the prototypical GPCR rhodopsin, and ligand docking were performed to identify PAR2 transmembrane (TM) amino acids potentially involved in agonist binding. These methods identified 12 candidate residues that were mutated to examine the binding site of the PAR2 TL, revealed by trypsin cleavage, as well as of the soluble ligands 2f-LIGRLO-NH2 and GB110, which are both structurally based on the AP SLIGRLNH2. Ligand binding was evaluated from the impact of the mutated residues on PAR2-mediated calcium mobilisation. An important finding from these experiments was that mutation of residues Y156 and Y326 significantly reduced 2f-LIGRLO-NH2 and GB110 agonist activity. L307 was also important for GB110 activity. Intriguingly, mutation of PAR2 residues did not alter trypsin-induced signalling to the same extent as for the soluble agonists. The reason for this difference remains to be further examined by in silico and in vitro experimentation and, potentially, crystal structure studies. However, these findings identified the importance of TM domains in PAR2 ligand docking and will enhance the design of both PAR2 agonists and potentially agents to inhibit signalling (antagonists). The potential importance of PAR2 in prostate cancer bone metastasis was examined using a mouse model. In patients, prostate cancer bone metastases cause bone growth by disrupting bone homeostasis. In an attempt to mimic prostate cancer growth in bone, PAR2 responsive 22Rv1 prostate cancer cells, which form mixed osteoblastic and osteolytic lesions, were injected into the proximal aspect of mouse tibiae. A role for PAR2 was assessed by treating these mice with the recently developed PAR2 antagonist GB88. As controls, animals bearing intra-tibial tumours were also treated with vehicle (olive oil) or the prostate cancer chemotherapeutic docetaxel. The effect of these treatments on bone was examined radiographically and by micro-CT. Consistent with previous studies, 22Rv1 tumours caused osteoblastic periosteal spicule formation and concurrent osteolytic bone loss. Significantly, blockade of PAR2 signalling reduced the osteoblastic and osteolytic phenotype of 22Rv1 tumours in bone. No bone defects were detected in mice treated with docetaxel. These qualitative data will be followed in the future by quantitative micro-CT analysis as well as histology and histomorphometry analysis of already collected tissues. Nonetheless, these preliminary experiments highlight a potential role for PAR2 in prostate cancer growth in bone. In summary, in vitro studies have defined mechanisms regulating PAR2 activation, downstream signalling and trafficking and in vivo studies point to a potential role for this receptor in prostate cancer bone metastasis. The outcomes of this project are that a greater understanding of the biology of PAR2 may lead to the development of strategies to modulate the function of this receptor in disease.

Rotorcraft collision avoidance using spherical image-based visual servoing and single point features

This paper presents a reactive collision avoidance method for small unmanned rotorcraft using spherical image-based visual servoing. Only a single point feature is used to guide the aircraft in a safe spiral like trajectory around the target, whilst a spherical camera model ensures the target always remains visible. A decision strategy to stop the avoidance control is derived based on the properties of spiral like motion, and the effect of accurate range measurements on the control scheme is discussed. We show that using a poor range estimate does not significantly degrade the collision avoidance performance, thus relaxing the need for accurate range measurements. We present simulated and experimental results using a small quad rotor to validate the approach.

From the Editor

The five articles appearing in this issue reflect the depth of project management research in terms of delineating and clarifying the different philosophical positions, advancing the concepts, and applying innovative research methods. These articles focus on the ontology of project management research (“Foundations of Project Management Research: An Explicit and Six-Facet Ontological Framework” by Gauthier and Ika), project management practices relevant to different types of projects from a practitioner’s perspective (“An Empirical Identification of Project Management Toolsets and a Comparison Among Project Types” by Besner and Hobbs), the effect of project management processes on project performance (“Project Management Knowledge and Effects on Construction Project Outcomes: An Empirical Study” by Chou and Yang), determining the success metrics at different stages of a project (“A Perspective Based Understanding of Project Success” by McLeod, Doolin, and MacDonell), and identifying project success parameters and critical success factors from the point of view of different project actors in largescale projects (“Forecasting Success on Large Projects: Developing Reliable Scales to Predict Multiple Perspectives by Multiple Stakeholders Over Multiple Time Frames” by Turner and Zolin), and understanding project success from the points of view of different project stakeholders...

The relationship between drivers’ perceptions toward police speed enforcement and self-reported speeding behaviour

Exceeding the speed limit and driving too fast for the conditions are regularly cited as significant contributing factors in traffic crashes, particularly fatal and serious injury crashes. Despite an extensive body of research highlighting the relationship between increased vehicle speeds and crash risk and severity, speeding remains a pervasive behaviour on Australian roads. The development of effective countermeasures designed to reduce the prevalence of speeding behaviour requires that this behaviour is well understood. The primary aim of this program of research was to develop a better understanding of the influence of drivers’ perceptions and attitudes toward police speed enforcement on speeding behaviour. Study 1 employed focus group discussions with 39 licensed drivers to explore the influence of perceptions relating to specific characteristics of speed enforcement policies and practices on drivers’ attitudes towards speed enforcement. Three primary factors were identified as being most influential: site selection; visibility; and automaticity (i.e., whether the enforcement approach is automated/camera-based or manually operated). Perceptions regarding these enforcement characteristics were found to influence attitudes regarding the perceived legitimacy and transparency of speed enforcement. Moreover, misperceptions regarding speed enforcement policies and practices appeared to also have a substantial impact on attitudes toward speed enforcement, typically in a negative direction. These findings have important implications for road safety given that prior research has suggested that the effectiveness of speed enforcement approaches may be reduced if efforts are perceived by drivers as being illegitimate, such that they do little to encourage voluntary compliance. Study 1 also examined the impact of speed enforcement approaches varying in the degree of visibility and automaticity on self-reported willingness to comply with speed limits. These discussions suggested that all of the examined speed enforcement approaches (see Section 1.5 for more details) generally showed potential to reduce vehicle speeds and encourage compliance with posted speed limits. Nonetheless, participant responses suggested a greater willingness to comply with approaches operated in a highly visible manner, irrespective of the corresponding level of automaticity of the approach. While less visible approaches were typically associated with poorer rates of driver acceptance (e.g., perceived as “sneaky” and “unfair”), participants reported that such approaches would likely encourage long-term and network-wide impacts on their own speeding behaviour, as a function of the increased unpredictability of operations and increased direct (specific deterrence) and vicarious (general deterrence) experiences with punishment. Participants in Study 1 suggested that automated approaches, particularly when operated in a highly visible manner, do little to encourage compliance with speed limits except in the immediate vicinity of the enforcement location. While speed cameras have been criticised on such grounds in the past, such approaches can still have substantial road safety benefits if implemented in high-risk settings. Moreover, site-learning effects associated with automated approaches can also be argued to be a beneficial by-product of enforcement, such that behavioural modifications are achieved even in the absence of actual enforcement. Conversely, manually operated approaches were reported to be associated with more network-wide impacts on behaviour. In addition, the reported acceptance of such methods was high, due to the increased swiftness of punishment, ability for additional illegal driving behaviours to be policed and the salutary influence associated with increased face-to-face contact with authority. Study 2 involved a quantitative survey conducted with 718 licensed Queensland drivers from metropolitan and regional areas. The survey sought to further examine the influence of the visibility and automaticity of operations on self-reported likelihood and duration of compliance. Overall, the results from Study 2 corroborated those of Study 1. All examined approaches were again found to encourage compliance with speed limits, such that all approaches could be considered to be “effective”. Nonetheless, significantly greater self-reported likelihood and duration of compliance was associated with visibly operated approaches, irrespective of the corresponding automaticity of the approach. In addition, the impact of automaticity was influenced by visibility; such that significantly greater self-reported likelihood of compliance was associated with manually operated approaches, but only when they are operated in a less visible fashion. Conversely, manually operated approaches were associated with significantly greater durations of self-reported compliance, but only when they are operated in a highly visible manner. Taken together, the findings from Studies 1 and 2 suggest that enforcement efforts, irrespective of their visibility or automaticity, generally encourage compliance with speed limits. However, the duration of these effects on behaviour upon removal of the enforcement efforts remains questionable and represents an area where current speed enforcement practices could possibly be improved. Overall, it appears that identifying the optimal mix of enforcement operations, implementing them at a sufficient intensity and increasing the unpredictability of enforcement efforts (e.g., greater use of less visible approaches, random scheduling) are critical elements of success. Hierarchical multiple regression analyses were also performed in Study 2 to investigate the punishment-related and attitudinal constructs that influence self-reported frequency of speeding behaviour. The research was based on the theoretical framework of expanded deterrence theory, augmented with three particular attitudinal constructs. Specifically, previous research examining the influence of attitudes on speeding behaviour has typically focussed on attitudes toward speeding behaviour in general only. This research sought to more comprehensively explore the influence of attitudes by also individually measuring and analysing attitudes toward speed enforcement and attitudes toward the appropriateness of speed limits on speeding behaviour. Consistent with previous research, a number of classical and expanded deterrence theory variables were found to significantly predict self-reported frequency of speeding behaviour. Significantly greater speeding behaviour was typically reported by those participants who perceived punishment associated with speeding to be less certain, who reported more frequent use of punishment avoidance strategies and who reported greater direct experiences with punishment. A number of interesting differences in the significant predictors among males and females, as well as younger and older drivers, were reported. Specifically, classical deterrence theory variables appeared most influential on the speeding behaviour of males and younger drivers, while expanded deterrence theory constructs appeared more influential for females. These findings have important implications for the development and implementation of speeding countermeasures. Of the attitudinal factors, significantly greater self-reported frequency of speeding behaviour was reported among participants who held more favourable attitudes toward speeding and who perceived speed limits to be set inappropriately low. Disappointingly, attitudes toward speed enforcement were found to have little influence on reported speeding behaviour, over and above the other deterrence theory and attitudinal constructs. Indeed, the relationship between attitudes toward speed enforcement and self-reported speeding behaviour was completely accounted for by attitudes toward speeding. Nonetheless, the complexity of attitudes toward speed enforcement are not yet fully understood and future research should more comprehensively explore the measurement of this construct. Finally, given the wealth of evidence (both in general and emerging from this program of research) highlighting the association between punishment avoidance and speeding behaviour, Study 2 also sought to investigate the factors that influence the self-reported propensity to use punishment avoidance strategies. A standard multiple regression analysis was conducted for exploratory purposes only. The results revealed that punishment-related and attitudinal factors significantly predicted approximately one fifth of the variance in the dependent variable. The perceived ability to avoid punishment, vicarious punishment experience, vicarious punishment avoidance and attitudes toward speeding were all significant predictors. Future research should examine these relationships more thoroughly and identify additional influential factors. In summary, the current program of research has a number of implications for road safety and speed enforcement policy and practice decision-making. The research highlights a number of potential avenues for the improvement of public education regarding enforcement efforts and provides a number of insights into punishment avoidance behaviours. In addition, the research adds strength to the argument that enforcement approaches should not only demonstrate effectiveness in achieving key road safety objectives, such as reduced vehicle speeds and associated crashes, but also strive to be transparent and legitimate, such that voluntary compliance is encouraged. A number of potential strategies are discussed (e.g., point-to-point speed cameras, intelligent speed adaptation. The correct mix and intensity of enforcement approaches appears critical for achieving optimum effectiveness from enforcement efforts, as well as enhancements in the unpredictability of operations and swiftness of punishment. Achievement of these goals should increase both the general and specific deterrent effects associated with enforcement through an increased perceived risk of detection and a more balanced exposure to punishment and punishment avoidance experiences.

Food for thought : designing for critical reflection on food practices

This workshop is a continuation and extension to the successful past workshops including [4, 5, 6]. The workshop addresses the opportunities and challenges for the design of digital interactive systems that engage individuals in critical reflection on their everyday food practices - including designing for engagement in more environmentally aware, socially inclusive, and healthier behaviour. These three themes represent the focus of much recent HCI work related to food. The workshop aims to further the conversation on these themes through understanding specifically how the process of critical reflection can be encouraged by interactive technology. While the focus will be on food as an application area, the intention is to also explore, more generally, how the process of critical reflection can be facilitated through interactive technology. The workshop provides a unique forum to discuss existing theoretical and pragmatic approaches, and to envision novel ways to design technology that encourages sustained critical reflection.

The active site residue V266 of Chlamydial HtrA is critical for substrate binding during both in vitro and in vivo conditions

HtrA is a complex, multimeric chaperone and serine protease important for the virulence and survival of many bacteria. Chlamydia trachomatis is an obligate, intracellular bacterial pathogen that is responsible for severe disease pathology. C. trachomatis HtrA (CtHtrA) has been shown to be highly expressed in laboratory models of disease. In this study, molecular modelling of CtHtrA protein active site structure identified putative S1-S3 subsite residues I242, I265, and V266. These residues were altered by site-directed mutagenesis, and these changes were shown to considerably reduce protease activity on known substrates and resulted in a narrower and distinct range of substrates compared to wild type. Bacterial two-hybrid analysis revealed that CtHtrA is able to interact in vivo with a broad range of protein sequences with high affinity. Notably, however, the interaction was significantly altered in 35 out of 69 clones when residue V266 was mutated, indicating that this residue has an important function during substrate binding.

State cycles, initialization and the Trivium stream cipher

Trivium is a keystream generator for a binary additive synchronous stream cipher. It was selected in the final portfolio for the Profile 2 category of the eSTREAM project. The keystream generator is constructed using bit- based shift registers. In this paper we present an alternate representation of Trivium using word-based shift registers, with a word size of three bits. This representation is useful for determining cycles of internal state values. Under this representation it is clear that the state space can be partitioned into subspaces and that over some of these subspaces the state update function is effectively linear. The role of the initialization process is critical in ensuring the states used for generating keystream are updated nonlinearly at some point, as the state update function alone does not provide this.

Defining critical literacy

This article traces the lineage of critical literacy from Freire through critical pedagogies and discourse analysis. The author discusses the need for a contingent definition of critical literacy, as a situated and contextual response to political economies, institutional and cultural relations of power.

Performing design: game design, practice, praxis and the theatre of the impressed

This paper is a reflection on a design teaching project that endeavours to establish a culture of critical design thinking in a tertiary game design course. In the first instance, the ‘performing design’ project arose as a response to contemporary issues and tensions in the Australian games industry and game design education, in essence, the problem of how to scaffold undergraduate students from their entry point as ‘players’ (the impressed) into becoming designers. The performing design project therefore started as a small-scale intervention to inspire reflection in a wider debate that includes: the potential evolution of the contemporary games industry; the purpose of game design education; and the positioning of game design as a design discipline. Our position is that designing interactive playful works or games is victim of a tendency to simplify the discipline and view it from either the perspective of science or art. In this paper we look at some of the historical discussions on the distinct identity of games. Then we present an overview of the typical state of play in contemporary game design education which inspires the performing design project as an intervention or teaching technique. This leads us to question understandings of education and training and creativity and innovation. Finally we reflect on insights arising from the performing design project which lead us to support Archer’s call for a ‘third area’ that balances the monolithic practices of the two major academic disciplines.

GLBTI police liaison services : a critical analysis of existing literature

GLBTI (gay, lesbian, bisexual, transgender, intersex) police liaison programs have been an important part of policing these communities for a number of decades now. In fact, this model appears to dominate approaches as the preferred way to manage relationships between GLBTI communities and police. Interestingly, while this model dominates, research on the effectiveness of this model, and the services that align with it, is limited. To date, only few studies have asked critical questions about the effectiveness of GLBTI police liaison services. For instance, we know that over 70% of GLBTI communities are aware of police liaison services, but only 4% of those victimised access them (Berman & Robinson, 2010). This paper critically examines existing literature about GLBTI police liaison services to demonstrate key themes and omissions. It argues that police liaison services as a preferred model has been taken for granted as the correct way of engaging with GLBTI communities in ways that may exclude other forms of engagement, and suggests that further research into these liaison programs is necessary if the relationships between GLBTI communities and the police are to be strengthened.

When the right to be counted doesn’t count : the politics and challenges of researching the health of asylum seekers

A fundamental prerequisite of population health research is the ability to establish an accurate denominator. This in turn requires that every individual in the study population is counted. However, this seemingly simple principle has become a point of conflict between researchers whose aim is to produce evidence of disparities in population health outcomes and governments whose policies promote(intentionally or not) inequalities that are the underlying causes of health disparities. Research into the health of asylum seekers is a case in point. There is a growing body of evidence documenting the adverse affects of recent changes in asylum-seeking legislation, including mandatory detention. However, much of this evidence has been dismissed by some governments as being unsound, biased and unscientific because, it is argued, evidence is derived from small samples or from case studies. Yet, it is the policies of governments that are the key barrier to the conduct of rigorous population health research on asylum seekers. In this paper, the authors discuss the challenges of counting asylum seekers and the limitations of data reported in some industrialized countries. They argue that the lack of accurate statistical data on asylum seekers has been an effective neo-conservative strategy for erasing the health inequalities in this vulnerable population, indeed a strategy that renders invisible this population. They describe some alternative strategies that may be used by researchers to obtain denominator data on hard-to-reach populations such as asylum seekers.