Flexural-torsional buckling tests of cold-formed steel compression members at elevated temperatures

Current design standards do not provide adequate guidelines for the fire design of cold-formed steel compression members subject to flexural-torsional buckling. Eurocode 3 Part 1.2 (2005) recommends the same fire design guidelines for both hot-rolled and cold-formed steel compression members subject to flexural-torsional buckling although considerable behavioural differences exist between cold-formed and hot-rolled steel members. Past research has recommended the use of ambient temperature cold-formed steel design rules for the fire design of cold-formed steel compression members provided appropriately reduced mechanical properties are used at elevated temperatures. To assess the accuracy of flexural-torsional buckling design rules in both ambient temperature cold-formed steel design and fire design standards, an experimental study of slender cold-formed steel compression members was undertaken at both ambient and elevated temperatures. This paper presents the details of this experimental study, its results, and their comparison with the predictions from the current design rules. It was found that the current ambient temperature design rules are conservative while the fire design rules are overly conservative. Suitable recommendations have been made in relation to the currently available design rules for flexural-torsional buckling including methods of improvement. Most importantly, this paper has addressed the lack of experimental results for slender cold-formed steel columns at elevated temperatures.

Solo life to Second Life : the design of physical and virtual learning spaces inspired by the drama classroom

This paper explores the design of virtual and physical learning spaces developed for students of drama and theatre studies. What can we learn from the traditional drama workshop that will inform the design of drama and theatre spaces created in technology-mediated learning environments? The authors examine four examples of spaces created for online, distance and on-campus students and discuss the relationship between the choice of technology, the learning and teaching methods, and the outcomes for student engagement. Combining insights from two previous action research projects, the discussion focuses on the physical space used for contemporary drama workshops, supplemented by Web 2.0 technologies; a modular online theatre studies course; the blogging space of students creating a group devised play; and the open and immersive world of Second Life, where students explore 3D simulations of historical theatre sites. The authors argue that the drama workshop can be used as inspiration for the design of successful online classrooms. This is achieved by focusing on students’ contributions to the learning as individuals and group members, the aesthetics and mise-en-scene of the learning space, and the role of mobile and networked technologies. Students in this environment increase their capacity to become co-creators of knowledge and to achieve creative outcomes. The drama workshop space in its physical and virtual forms is seen as a model for classrooms in other disciplines, where dynamic, creative and collaborative spaces are required.

Assessment bias : physical activity questionnaire assessment inadvertently influences patients’ desire to be ‘more physically active’

Evaluating physical activity is important for public health population research and evaluating lifestyle interventions among targeted groups. Self-reported questionnaires are frequently used to evaluate physical activity in a variety of contexts where resource or pragmatic limitations prohibit the use of more sophisticated approaches. However, prior research in the use of other patient reported outcomes in healthcare settings has highlighted that simply completing a questionnaire may change a patients’ behaviour or responses to subsequent questions. This methodology study aimed to examine whether completing a standard physical activity questionnaire altered patients responses to two related questions a) whether they are ‘sufficiently physically active’ and b) whether they desire ‘to be more physically active.’

Physical activity amongst people with chronic back pain : an investigation of perceived barriers and facilitators to inform intervention development

Previous research has indicated people with non-specific low back pain who are physically inactive face a poorer prognosis than people with back pain who participate in low or moderate intensity physical activity. They also face a greater risk of other lifestyle related health conditions, such as diabetes and heart disease. For these reasons, contemporary non-surgical interventions for low back pain aim to incorporate a return to physical activity. However, there is a lack of empirical evidence supporting physical activity interventions for this purpose. It is likely that people with low back pain face additional challenges when trying to commence (or return to) regular physical activity. This exploratory qualitative research aimed to map out perceived barriers and facilitators to undertaking physical activity among people with non-specific low back pain to inform future intervention development.

Physical activity amongst older adults with musculoskeletal disorders : a descriptive study

"The World Health Organisation has identified physical inactivity as the fourth leading effective cause of death globally. The burden of physical inactivity will increase as the population ages. In addition to increased risk or mortality, prior research has indicated older adults with chronic musculoskeletal conditions are likely to face increased morbidity and poorer prognoses if they are physically inactive. There is currently a scarcity of empirical research describing the physical activity profile of older adults with chronic musculoskeletal disorders. The aim of this investigation was to describe the self-reported physical activity profile and body mass index (BMI) profile of a sample of older adults with chronic musculoskeletal disorders accessing outpatient hospital services."--publisher website

Recruiting and engaging new mothers in nutrition research studies : lessons from the Australian NOURISH randomised controlled trial

Background: Despite important implications for the budgets, statistical power and generalisability of research findings, detailed reports of recruitment and retention in randomised controlled trials (RCTs) are rare. The NOURISH RCT evaluated a community-based intervention for first-time mothers that promoted protective infant feeding practices as a primary prevention strategy for childhood obesity. The aim of this paper is to provide a detailed description and evaluation of the recruitment and retention strategies used. Methods: A two stage recruitment process designed to provide a consecutive sampling framework was used. First time mothers delivering healthy term infants were initially approached in postnatal wards of the major maternity services in two Australian cities for consent to later contact (Stage 1). When infants were about four months old mothers were re-contacted by mail for enrolment (Stage 2), baseline measurements (Time 1) and subsequent random allocation to the intervention or control condition. Outcomes were assessed at infant ages 14 months (Time 2) and 24 months (Time 3). Results: At Stage 1, 86% of eligible mothers were approached and of these women, 76% consented to later contact. At Stage 2, 3% had become ineligible and 76% could be recontacted. Of the latter, 44% consented to full enrolment and were allocated. This represented 21% of mothers screened as eligible at Stage 1. Retention at Time 3 was 78%. Mothers who did not consent or discontinued the study were younger and less likely to have a university education. Conclusions: The consent and retention rates of our sample of first time mothers are comparable with or better than other similar studies. The recruitment strategy used allowed for detailed information from non-consenters to be collected; thus selection bias could be estimated. Recommendations for future studies include being able to contact participants via mobile phone (particular text messaging), offering home visits to reduce participant burden and considering the use of financial incentives to support participant retention.

Iterative development of MobileMums : a physical activity intervention for women with young children.

Background To describe the iterative development process and final version of ‘MobileMums’: a physical activity intervention for women with young children (<5 years) delivered primarily via mobile telephone (mHealth) short messaging service (SMS). Methods MobileMums development followed the five steps outlined in the mHealth development and evaluation framework: 1) conceptualization (critique of literature and theory); 2) formative research (focus groups, n= 48); 3) pre-testing (qualitative pilot of intervention components, n= 12); 4) pilot testing (pilot RCT, n= 88); and, 5) qualitative evaluation of the refined intervention (n= 6). Results Key findings identified throughout the development process that shaped the MobileMums program were the need for: behaviour change techniques to be grounded in Social Cognitive Theory; tailored SMS content; two-way SMS interaction; rapport between SMS sender and recipient; an automated software platform to generate and send SMS; and, flexibility in location of a face-to-face delivered component. Conclusions The final version of MobileMums is flexible and adaptive to individual participant’s physical activity goals, expectations and environment. MobileMums is being evaluated in a community-based randomised controlled efficacy trial (ACTRN12611000481976).

Using photography in ‘The Restaurant of the Future’. A useful way to assess portion selection and plate cleaning?

Laboratory-based studies of human dietary behaviour benefit from highly controlled conditions; however, this approach can lack ecological validity. Identifying a reliable method to capture and quantify natural dietary behaviours represents an important challenge for researchers. In this study, we scrutinised cafeteria-style meals in the ‘Restaurant of the Future.’ Self-selected meals were weighed and photographed, both before and after consumption. Using standard portions of the same foods, these images were independently coded to produce accurate and reliable estimates of (i) initial self-served portions, and (ii) food remaining at the end of the meal. Plate cleaning was extremely common; in 86% of meals at least 90% of self-selected calories were consumed. Males ate a greater proportion of their self-selected meals than did females. Finally, when participants visited the restaurant more than once, the correspondence between selected portions was better predicted by the weight of the meal than by its energy content. These findings illustrate the potential benefits of meal photography in this context. However, they also highlight significant limitations, in particular, the need to exclude large amounts of data when one food obscures another.

Detecting conversing groups of chatters : a model, algorithms, and tests

Chatrooms, for example Internet Relay Chat, are generally multi-user, multi-channel and multiserver chat-systems which run over the Internet and provide a protocol for real-time text-based conferencing between users all over the world. While a well-trained human observer is able to understand who is chatting with whom, there are no efficient and accurate automated tools to determine the groups of users conversing with each other. A precursor to analysing evolving cyber-social phenomena is to first determine what the conversations are and which groups of chatters are involved in each conversation. We consider this problem in this paper. We propose an algorithm to discover all groups of users that are engaged in conversation. Our algorithms are based on a statistical model of a chatroom that is founded on our experience with real chatrooms. Our approach does not require any semantic analysis of the conversations, rather it is based purely on the statistical information contained in the sequence of posts. We improve the accuracy by applying some graph algorithms to clean the statistical information. We present some experimental results which indicate that one can automatically determine the conversing groups in a chatroom, purely on the basis of statistical analysis.

A safe system-based approach to selection of clear zones, safety barriers and other roadside treatments

On average, 560 fatal run-off-road crashes occur annually in Australia and 135 in New Zealand. In addition, there are more than 14,000 run-off-road crashes causing injuries each year across both countries. In rural areas, run-off-road casualty crashes constitute 50-60% of all casualty crashes. Their severity is particularly high with more than half of those involved sustaining fatal or serious injuries. This paper reviews the existing approach to roadside hazard risk assessment, selection of clear zones and hazard treatments. It proposes a modified approach to roadside safety evaluation and management. It is a methodology based on statistical modelling of run-off-road casualty crashes, and application of locally developed crash modification factors and severity indices. Clear zones, safety barriers and other roadside design/treatment options are evaluated with a view to minimise fatal and serious injuries – the key Safe System objective. The paper concludes with a practical demonstration of the proposed approach. The paper is based on findings from a four-year Austroads research project into improving roadside safety in the Safe System context.

Airborne collision scenario flight tests : impact of angle measurement errors on reactive vision-based avoidance control

The future emergence of many types of airborne vehicles and unpiloted aircraft in the national airspace means collision avoidance is of primary concern in an uncooperative airspace environment. The ability to replicate a pilot’s see and avoid capability using cameras coupled with vision based avoidance control is an important part of an overall collision avoidance strategy. But unfortunately without range collision avoidance has no direct way to guarantee a level of safety. Collision scenario flight tests with two aircraft and a monocular camera threat detection and tracking system were used to study the accuracy of image-derived angle measurements. The effect of image-derived angle errors on reactive vision-based avoidance performance was then studied by simulation. The results show that whilst large angle measurement errors can significantly affect minimum ranging characteristics across a variety of initial conditions and closing speeds, the minimum range is always bounded and a collision never occurs.

Incentive-based interventions for increasing physical activity and fitness

This is the protocol for a review and there is no abstract. The objectives are as follows: The main aim of the review is to determine the effectiveness of using incentive-based approaches (IBAs) (financial and non-financial) to increase physical activity in community-dwelling children and adults. A secondary objective will be to address the use of incentives to improve cardiovascular and metabolic fitness. A final objective will be to explore: - whether there are any adverse effects associated with the use of IBAs for increasing physical activity; - whether there are any differential effects of IBAs within and between study populations by age, gender, education, inequalities and health status; and - whether the use of disincentive/aversive approaches leads to a reduction in sedentary behaviour.

Community interventions for physical activity : the role of a new Cochrane systematic review

Introduction: Systematic reviews are essential in summarising the results of a range of research studies on a specific topic into a single report. They serve as a key source of evidence-based information to support and develop policy and practice for healthy communities. This presentation will examine a new review of community-wide strategies to increase population levels of physical activity and compare it to an earlier Community Guide Review (CGR) of Community-wide campaigns to increase physical activity which recommended community wide interventions. Methods: We registered a Cochrane Systematic Review (CSR) title, published a protocol and recently completed the review of Community-wide interventions to increase physical activity. We compared the definitions, design and findings of the CSR to the CGR. Results: The two reviews differed remarkably in their conclusions with the CGR recommending “strong evidence exists that community-wide campaigns are effective in increasing levels of physical activity”, and the new CSR stating “The body of evidence in this review does not support the hypothesis that multi-component community wide interventions effectively increase population levels of physical activity”. We observed that both reviews examined multi-component interventions as a “combined package”. Possible explanations for the different conclusions may be due to the definition of community (CSR defined community as “comprising those persons residing in a geographically defined community, such as a village, town, or city”, excluding interventions which were whole of state or country, and CGR as “a group of individuals who share one or more characteristics. The CSR utilised a logic model at various stages of the review process and explicitly defined a combination of strategies encompassed within the intervention. The CSR included 25 and CGR 10 studies, respectively. Six of the 10 studies that were included in CGR were excluded from the CSR due to issues relating to study design, intervention definition or duration. The two reviews also differ in function as the CSR seeks to summarise global evidence and included 7 studies in low-income countries, where as the CGR contained only studies deemed relevant to the USA context. Discussion: Differences in the findings between older and newer reviews can be due to a variety of factors. For example, in updating a review the definition of an intervention can be changed. Further, differences may also be due to improvements in the standards and methodologies for systematic reviews as well as the inclusion of newer studies. These factors need to be understood whenever differences between newer and older reviews are considered.

Methodological challenges in conducting a systematic review of community wide interventions to increase physical activity

Introduction: Evaluating the effectiveness of interventions designed to increase the physical activity in communities is often a difficult and complex task, requiring considerable expertise and investment, and often constrained by methodological limitations. These limitations, in turn, create additional challenges when these studies are used in systematic reviews as they hinder the confidence, precision and interpretation of results. The objective of this paper is to summarise the methodological challenges posed in conducting a systematic review of community-wide physical activity interventions to help inform those conducting future primary research and systematic reviews. Methods: We conducted a Cochrane systematic review of community-wide interventions to increase physical activity. We assessed the methodological quality of the included studies. We will investigate these in greater detail, particularly in relation to the potential impact on measures of effect, confidence in results, generalizability of results and general interpretation. Results: The systematic review was conducted and has been published in the Cochrane Library. A logic model was helpful in defining and interpreting the studies. Many studies of unsuitable study design were excluded; however several important methodological limitations of the primary studies evaluating community-wide physical activity interventions emerged. These included: - the failure to use validated tools to measure physical activity; - issues associated with pre and post test designs; - inadequate sampling of populations; - poor control groups; and - intervention and measurement protocols of inadequate duration. Although it is challenging to undertake rigorous evaluations of complex interventions, these issues result in significant uncertainty over the effectiveness of these interventions, and the possible factors required for a community-wide intervention to be successful. In particular, the combination of several of these limitations (e.g. un-validated tools, inadequate sampling, and short duration) is that studies may lack the sensitivity to detect any meaningful change. Multiple publications of findings for the same study also made interpretation difficult; however, interventions with parallel qualitative publications were helpful. Discussion: Evaluating community wide interventions to increase physical activity in a rigorous way is incredibly challenging. These findings reflect these challenges but have important ramifications for researchers conducting primary studies to determine the efficacy of such interventions, as well as for researchers conducting systematic reviews. This new review shows that the inadequacies of design and evaluation are continuing. It is hoped that the adoption of such suggestions may aid in the development of systematic reviews, but more importantly, in enabling translation of such findings into policy and practice.