Segmentation of cone-beam CT using a hidden Markov random field with informative priors

Cone-beam computed tomography (CBCT) has enormous potential to improve the accuracy of treatment delivery in image-guided radiotherapy (IGRT). To assist radiotherapists in interpreting these images, we use a Bayesian statistical model to label each voxel according to its tissue type. The rich sources of prior information in IGRT are incorporated into a hidden Markov random field model of the 3D image lattice. Tissue densities in the reference CT scan are estimated using inverse regression and then rescaled to approximate the corresponding CBCT intensity values. The treatment planning contours are combined with published studies of physiological variability to produce a spatial prior distribution for changes in the size, shape and position of the tumour volume and organs at risk. The voxel labels are estimated using iterated conditional modes. The accuracy of the method has been evaluated using 27 CBCT scans of an electron density phantom. The mean voxel-wise misclassification rate was 6.2\%, with Dice similarity coefficient of 0.73 for liver, muscle, breast and adipose tissue. By incorporating prior information, we are able to successfully segment CBCT images. This could be a viable approach for automated, online image analysis in radiotherapy.

Storytelling beyond the anthropocene : a quest through the crises of ecocide toward new ecological paradigms

This project is a passionate and sometimes enraged thrust toward a biodiverse future. Weaving stories with deep thinking beyond the limits of the anthropocene, I am trying to recall myself in a more-than-human world. Our planet is suffering human induced ecocide which is a global crisis threatening the existence of multiple life forms. The alchemical mix of storytelling and ecological thinking could be part remedy for humanity's adaptation: a transformational mix to re-pattern the crisis into an opportunity and shift anthropocentric structures toward networks of dynamic relationships. The purpose of this project is to explore this cultural remedy. This is a quest, a search for tools that can germinate the hypothesis: storytelling in relation to ecological thinking manifests human potential in a more-than-human world. The practice-led research is guided by the philosophy and practice of Mythology, Deep ecology and Transdisciplinarity. Further navigation is sourced from Systems Thinking, Indigenous Methodologies, Biomimicry, and Quantum Physics. The journey unfolds by reawakening the Artist's function as caretaker of Mythology and pattern inciter for the collective. The resounding discovery of this adventure is Quantum Narratives: a storytelling tool for today's world, a method to connect multiple ways of knowing and diverse languages with the purpose of engaging, relating and working with living knowledge. Quantum Narratives are used to test the field study research into the Future of Water in context of Coal Seam Gas Mining in the Murray-Darling Basin and to materialise the collaborative results as the Water Stories. This thesis is a Living Script, full of imagination and complexity. Within its folds are strategies for systemic change ready to be adapted by policy and planning brokers and those who hold power for widespread remedial action.

A novel representation of bioacoustic events for content-based search in field audio data

Bioacoustic data can provide an important base for environmental monitoring. To explore a large amount of field recordings collected, an automated similarity search algorithm is presented in this paper. A region of an audio defined by frequency and time bounds is provided by a user; the content of the region is used to construct a query. In the retrieving process, our algorithm will automatically scan through recordings to search for similar regions. In detail, we present a feature extraction approach based on the visual content of vocalisations – in this case ridges, and develop a generic regional representation of vocalisations for indexing. Our feature extraction method works best for bird vocalisations showing ridge characteristics. The regional representation method allows the content of an arbitrary region of a continuous recording to be described in a compressed format.

Protocol for a randomised blocked design study using telephone and text-messaging to support cardiac patients with diabetes : a cross cultural international collaborative project

Background The prevalence of type 2 diabetes is rising internationally. Patients with diabetes have a higher risk of cardiovascular events accounting for substantial premature morbidity and mortality, and health care expenditure. Given healthcare workforce limitations, there is a need to improve interventions that promote positive self-management behaviours that enable patients to manage their chronic conditions effectively, across different cultural contexts. Previous studies have evaluated the feasibility of including telephone and Short Message Service (SMS) follow up in chronic disease self-management programs, but only for single diseases or in one specific population. Therefore, the aim of this study is to evaluate the feasibility and short-term efficacy of incorporating telephone and text messaging to support the care of patients with diabetes and cardiac disease, in Australia and in Taiwan. Methods/design A randomised controlled trial design will be used to evaluate a self-management program for people with diabetes and cardiac disease that incorporates the use of simple remote-access communication technologies. A sample size of 180 participants from Australia and Taiwan will be recruited and randomised in a one-to-one ratio to receive either the intervention in addition to usual care (intervention) or usual care alone (control). The intervention will consist of in-hospital education as well as follow up utilising personal telephone calls and SMS reminders. Primary short term outcomes of interest include self-care behaviours and self-efficacy assessed at baseline and four weeks. Discussion If the results of this investigation substantiate the feasibility and efficacy of the telephone and SMS intervention for promoting self management among patients with diabetes and cardiac disease in Australia and Taiwan, it will support the external validity of the intervention. It is anticipated that empirical data from this investigation will provide valuable information to inform future international collaborations, while providing a platform for further enhancements of the program, which has potential to benefit patients internationally.

Dependence of residual amplitude noise in electro-optic phase modulators on the intensity distribution of the incident field

Our results demonstrate that photorefractive residual amplitude modulation (RAM) noise in electro-optic modulators (EOMs) can be reduced by modifying the incident beam intensity distribution. Here we report an order of magnitude reduction in RAM when beams with uniform intensity (flat-top) profiles, generated with an LCOS-SLM, are used instead of the usual fundamental Gaussian mode (TEM00). RAM arises from the photorefractive amplified scatter noise off the defects and impurities within the crystal. A reduction in RAM is observed with increasing intensity uniformity (flatness), which is attributed to a reduction in space charge field on the beam axis. The level of RAM reduction that can be achieved is physically limited by clipping at EOM apertures, with the observed results agreeing well with a simple model. These results are particularly important in applications where the reduction of residual amplitude modulation to 10^-6 is essential.

Incorporating spatial correlations into multispecies mean-field models

In biology, we frequently observe different species existing within the same environment. For example, there are many cell types in a tumour, or different animal species may occupy a given habitat. In modelling interactions between such species, we often make use of the mean field approximation, whereby spatial correlations between the locations of individuals are neglected. Whilst this approximation holds in certain situations, this is not always the case, and care must be taken to ensure the mean field approximation is only used in appropriate settings. In circumstances where the mean field approximation is unsuitable we need to include information on the spatial distributions of individuals, which is not a simple task. In this paper we provide a method that overcomes many of the failures of the mean field approximation for an on-lattice volume-excluding birth-death-movement process with multiple species. We explicitly take into account spatial information on the distribution of individuals by including partial differential equation descriptions of lattice site occupancy correlations. We demonstrate how to derive these equations for the multi-species case, and show results specific to a two-species problem. We compare averaged discrete results to both the mean field approximation and our improved method which incorporates spatial correlations. We note that the mean field approximation fails dramatically in some cases, predicting very different behaviour from that seen upon averaging multiple realisations of the discrete system. In contrast, our improved method provides excellent agreement with the averaged discrete behaviour in all cases, thus providing a more reliable modelling framework. Furthermore, our method is tractable as the resulting partial differential equations can be solved efficiently using standard numerical techniques.

Designing for human–food interaction : an introduction to the special issue on ‘food and interaction design’

With this special issue, we draw attention to the growing and diverse field of HCI researchers exploring the interstices of food, technology and everyday practices. This special issue builds on the CHI workshop of the same name (Comber et al., 2012a), where we brought together the community of researchers that take food as a point from which to understand people and design technology. The workshop aimed to ‘to attend to the practical and theoretical difficulties in designing for human–food interactions in everyday life’ identifying four thematic areas of food practices – health and wellbeing; sustainability; food experiences; and alternative food cultures. These practical and theoretical difficulties are evident in the papers that we present here, though the distinction between our four themes, premised by complexities of food practices, is a little less evident. Thus, in the papers that follow we explore how the social, technological, cultural and methodological intertwine in the field of human–food interaction.

Virtual world cultural probe

We have developed a virtual world environment for eliciting expert information from stakeholders. The intention is that the virtual world prompts the user to remember more about their work processes. Our example shows a sparse visualisation of the University of Vienna Department of Computer Science, our collaborators in this project.

Understanding cultural competence in a multicultural nursing workforce : registered nurses’ experience in Saudi Arabia

Purpose In Saudi Arabia, the health system is mainly staffed by expatriate nurses from different cultural and linguistic backgrounds. Given the potential risks this situation poses for patient care, it is important to understand how cultural diversity can be effectively managed in this multicultural environment. The purpose of this study was to explore notions of cultural competence with non-Saudi Arabian nurses working in a major hospital in Saudi Arabia. Design Face-to-face, audio-recorded, semistructured interviews were conducted with 24 non-Saudi Arabian nurses. Deductive data collection and analysis were undertaken drawing on Campinha-Bacote’s cultural competence model. The data that could not be explained by this model were coded and analyzed inductively. Findings Nurses within this culturally diverse environment struggled with the notion of cultural competence in terms of each other’s cultural expectations and those of the dominant Saudi culture. Discussion The study also addressed the limitations of Campinha-Bacote’s model, which did not account for all of the nurses’ experiences. Subsequent inductive analysis yielded important themes that more fully explained the nurses’ experiences in this environment. Implications for Practice The findings can inform policy, professional education, and practice in the multicultural Saudi setting.

Rethinking cultural sensitivity

The concept of cultural sensitivity is located within the tradition of anthropology and the history of colonisation and immigration in Australian society. This history provides a basis for examining the largely uncritical introduction of cultural considerations to the discipline of nursing. This paper argues that contemporary understandings of multiculturalism in nursing and health care policy tend to obscure, ignore and thus perpetuate notions of racial superiority. Recent works in transcultural nursing are med to illustrate the way in which ahistorical and therefore quite arbitrary traits are attributed to particular cultural groups. This perspective, given legitimacy in terms of cultural sensitivity, encourages political neutrality and thereby avoids questioning the discriminatory practices embedded in fundamental social relations.

Rethinking cultural sensitivity : a response to criticism

We welcome Olga Kanitsaki’s comments on our paper ‘Rethinking cultural sensitivity’ (Nursing Inquiry 1996 3: 3-10) and appreciate the opportunity to respond. The main point we seek to emphasize here is the fundamental difference between our position and that of Kanitsaki. Our analysis is based on the recognition that the term ‘culture’ is historically and politically grounded. Its meaning changes over time and its contemporary usage (and popularity) thus demands explanation. The analytical task we undertook in our work was to emphasize the politics of culture rather than posing the political as one of a number of cultural dimensions (alongside the social, religious or technological)...

Acute hamstring strain injury in track and field athletes : a 3-year observational study at the Penn Relay Carnival

Purpose To observe the incidence rates of hamstring strain injuries (HSIs) across different competition levels and ages during the Penn Relays Carnival. Methods Over a 3-year period all injuries treated by the medical staff were recorded. The type of injury, anatomic location, event in which the injury occurred, competition level and demographic data were documented. Absolute and relative HSI (per 1000 participants) were determined and odds ratios (OR) were calculated between genders, competition levels and events. Results Throughout the study period 48,473 athletes registered to participate in the Penn Relays Carnival, with 118 HSIs treated by the medical team. High school females displayed lesser risk of HSI than high school males (OR = 0.55, p = 0.021), and masters athletes were more likely than high school (OR = 4.26, p < 0.001) and college (OR = 3.55, p = 0.001) level athletes to suffer a HSI. The 4x400m relay displayed a greater likelihood of HSI compared to the 4x100m relay (OR = 1.77, p = 0.008). Conclusions High school males and masters levels athletes are most likely to suffer HSI, and there is higher risk in 400m events compared to 100m events.

The cultural impact of institutional remix : the formalisation of textual reappropriation within the ABC

In 2009, Mark Deuze proposed an updated approach to media studies to incorporate ‘media life’, a concept he suggests addresses the invisibleness of ubiquitous media. Media life provides a useful lens for researchers to understand the human condition in media and not with media. At a similar time, public service media (PSM) strategies have aligned audience participation with the so‐called Reithian trinity which suggest the PSB should inform, educate and entertain while performing its core values of public service broadcasting (Enli 2008). Remix within the PSM institution relies on audience participation, employing ‘the people formerly known as the audience’ (Rosen 2006) as cultural artifact producers, and draws on their experience from within the media. Remix as a practice then enables us to examine the shift of the core PSM values by understanding how audience participation, informed by a human condition mobilised from our existence of being in media and not merely with media. However, remix within PSM challenges the once elitist construction of meaning models with an egalitarian approach towards socially reappropriated texts, questioning its affect on the cultural landscape. This paper draws on three years of ethnographic data from within the Australian Broadcasting Corporation (ABC), exploring the remix culture of ABC Pool. ABC Pool operates under a Creative Commons licensing regime to enable remix practice under the auspices of the ABC. ABC Pool users provide a useful group of remix practitioners to examine as they had access to a vast ABC archival collection and were invited to remix those cultural artefacts, often adding cultural and fiscal value. This paper maintains a focus on the audience participation within PSM through remix culture by applying media dependency theory to remix as cultural practice and calls to expand and update the societal representation within the ABC.

Communication models of institutional online communities : the role of the ABC cultural intermediary

The co-creation of cultural artefacts has been democratised given the recent technological affordances of information and communication technologies. Web 2.0 technologies have enabled greater possibilities of citizen inclusion within the media conversations of their nations. For example, the Australian audience has more opportunities to collaboratively produce and tell their story to a broader audience via the public service media (PSM) facilitated platforms of the Australian Broadcasting Corporation (ABC). However, providing open collaborative production for the audience gives rise to the problem, how might the PSM manage the interests of all the stakeholders and align those interests with its legislated Charter? This paper considers this problem through the ABC’s user-created content participatory platform, ABC Pool and highlights the cultural intermediary as the role responsible for managing these tensions. This paper also suggests cultural intermediation is a useful framework for other media organisations engaging in co-creative activities with their audiences.

The role of the cultural intermediary within professional participatory communication : lessons from ABC Pool

As media institutions are encouraged to explore new production methodologies in the current economic crisis, they align with Schumpeter’s creative destruction provocation by exhibiting user-led political, organisation and socio-technical innovations. This paper highlights the significance of the cultural intermediary within the innovative, co-creative production arrangements for cultural artefacts by media professionals in institutional online communities. An institutional online community is defined as one that is housed, resourced and governed by commercial or non- commercial institutions and is not independently facilitated. Web 2.0 technologies have mobilised collaborative peer production activities for online content creation and professional media institutions face challenges in engaging participatory audiences in practices that are beneficial for all concerned stakeholders. The interests of those stakeholders often do not align, highlighting the need for an intermediary role that understands and translates the norms, rhetoric tropes and day-to-day activities between the individuals engaging in participatory communication activities for successful negotiation within the production process. This paper specifically explores the participatory relationship between the public service broadcaster (PSB), the Australian Broadcasting Corporation (ABC) and one of its online communities, ABC Pool (www.abc.net.au/pool). ABC Pool is an online platform developed and resourced by the ABC to encourage co-creation between audience members engaging in the production of user-generated content (UGC) and the professional producers housed within the ABC Radio Division. This empirical research emerges from a three-year research project where I employed an ethnographic action research methodology and was embedded at the ABC as the community manager of ABC Pool. In participatory communication environments, users favour meritocratic heterarchical governance over traditional institutional hierarchical systems (Malaby 2009). A reputation environment based on meritocracy requires an intermediary to identify the stakeholders, understand their interests and communicate effectively between them to negotiate successful production outcomes (Bruns 2008; Banks 2009). The community manager generally occupies this role, however it has emerged that other institutional production environments also employ an intermediary role under alternative monikers(Hutchinson 2012). A useful umbrella term to encompass the myriad of roles within this space is the cultural intermediary. The ABC has experimented with three institutional online community governance models that engage in cultural intermediation in differing decentralised capacities. The first and most closed is a single point of contact model where one cultural intermediary controls all of the communication of the participatory project. The second is a model of multiple cultural intermediaries engaging in communication between the institutional online community stakeholders simultaneously. The third is most open yet problematic as it promotes and empowers community participants to the level of cultural intermediaries. This paper uses the ABC Pool case study to highlight the differing levels of openness within cultural intermediation during the co-creative production process of a cultural artifact.