Effect of the glycemic index of carbohydrates on day-long (10 h) profiles of plasma glucose, insulin, cholecystokinin and ghrelin

Background: Low glycemic index (GI) carbohydrates have been linked to increased satiety. The drive to eat may be mediated by postprandial changes in glucose, insulin and gut peptides.
Objective: To investigate the effect of a low and a high GI diet on day-long (10 h) blood concentrations of glucose, insulin, cholecystokinin (CCK) and ghrelin (GHR).
Design: Subjects (n¼12) consumed a high and a low GI diet in a randomized, crossover design, consisting of four meals that were matched for macronutrients and fibre, and differed only in carbohydrate quality (GI). Blood was sampled every 30–60 min and assayed for glucose, insulin, CCK and GHR.
Results: The high GI diet resulted in significantly higher glucose and insulin mean incremental areas under the curve (IAUC, P¼0.027 and P¼0.001 respectively). CCK concentration was 59% higher during the first 7 h of the low GI diet (394±95 pmol/l min) vs the high GI diet (163±38 pmol/l min, P¼0.046), but there was no difference over 10 h (P¼0.224). GHR concentration was inversely correlated with insulin concentration (Pearson correlation 0.48, P¼0.007), but did not differ significantly between the low and high GI diets.
Conclusions: Mixed meals of lower GI are associated with lower day-long concentrations of glucose and insulin, and higher CCK after breakfast, morning tea and lunch. This metabolic profile could mediate differences in satiety and hunger seen in some, but not all, studies.

Active school playgrounds - myth or reality? Results of the "Move It Groove It" project

Background: School playgrounds during break times provide potential opportunities for children to be active during the school day. However, there is limited research on how active children really are during these breaks.

Methods: The CAST (Children's Activity Scanning Tool) instrument was developed, validated, and used to assess the percentages of children engaged in moderate to vigorous physical activity (MVPA) and vigorous physical activity (VPA—a subset of MVPA) in 18 primary schools (children ages 5–12) in rural Australia. Related environmental factors were also measured.

Results: For a school of median size (200 students), 51.4% of boys and 41.6% of girls were engaged in MVPA while 14.7% of boys and 9.4% of girls were engaged in VPA. Levels of engagement in MVPA and VPA were significantly higher during lunch periods than during recess. MVPA and VPA engagement in smaller schools was significantly higher than in larger schools.

Conclusions: With growing concern about children's physical activity (PA), school playgrounds offer an opportunity to increase children's MVPA engagement especially among girls. Consideration may be given to the lengthening of recess periods in order to increase PA levels. More research is needed to investigate factors affecting PA levels in larger schools.

Chaos rules : an exploration of the work of instructional designers in distance education

This thesis provides an examination of the work of instructional designers in distance education, through the conceptual lens of chaos theory. Chaos theory was chosen as an analytical tool because of its ability to reveal the patterns and processes of complex systems as they move between order and turbulence. Recent work in the social sciences, specifically literary theory, has provided impetus for applications of chaos theory to educational settings. Specifically, chaos theory is used to analyse eight case studies of projects volunteered by instructional designers working in five institutions in Hong Kong and Australia. Data were gathered over a period of months with each participant, chiefly through interviews, but also involving diary accounts, electronic mail and letters. The methodology was thus qualitative, specifically informed by Eisner's vision of the ‘critical connoisseur’. Eisner equates an ‘enlightened eye’ with attainment of the skills of a critical connoisseur. First, an effective qualitative researcher must develop connoisseurship, the art of appreciation. On its own, though, connoisseurship is not enough; it is a private act, and thus needs a public face or presence. Criticism is this link, criticism being the art of disclosure. The critical connoisseur aims to help others to increase perception and deepen understanding of an educational situation or event. In addition to the empirical work, a parallel strand of this thesis investigates the theory and reported practice of instructional design. A brief history of instructional design is presented, along with discussion of acknowledged deficiencies of current theory and approaches. Recent reported investigations of both theory and practice are analysed from the viewpoint of chaos theory. Examination of key contributions in the literature of instructional design and distance education reveals considerable resonance between these contributions and the fundamental properties of chaotic systems. Links are made, in both the theoretical and empirical strands, between instructional design and the behaviour of dissipative structures, attractors and the process of bifurcation. Use is also made of the time-dependent nature of chaos theory as a theory of becoming, rather than one of being. The thesis comprises eight chapters, two appendices and a references section. The introductory chapter explains the research problem, and outlines the structure of the thesis. Methodological considerations are left until after an assessment of instructional design literature and (reported) practice. This deliberately theoretical investigation (Chapters 2 and 3) comprises the first of the parallel strands that are presented. The basic conclusions are that instructional design theory has not been particularly helpful to or used by instructional designers, and that chaos theory might provide an alternative way of viewing instructional design practice. The other parallel strand is the empirical work, which for four chapters outlines the methodology and my findings concerning the role of instructional designers in distance education. The methodology is detailed in Chapter 4. Chapter 5 establishes the contexts of the participants, by examining their backgrounds and introductions to their roles. It also investigates their views on their role and status within their institutions and with working colleagues. Chapter 6 is an exploration of the major issues that influenced the work of the instructional designers. These are the issues that arose naturally in the interviews as the participants outlined the development and interactions that took place on a day to day basis. Time emerges as a key influence in their work, and its effects on the projects are outlined and analysed. The ways that instructional designers give advice to those with whom they work is also investigated. The next chapter continues consideration of their work, but this time as they reflect on their role and its demands. This includes their reactions to the various metaphors that have appeared in the literature, along with those that they introduced into our discussions. The links that are established between the two parallel strands are drawn more explicitly in the final chapter, Chapter 8, which is a notion of what a model of instructional design based on my conclusions might resemble. It summarises the evidence that it is not necessarily by striving for order—in fact quite the opposite — during key periods of course development, that leads to creative outcomes. The introduction of uncertainty and turbulence does, in some cases and under some conditions, move the system to a higher level. The image that is offered from chaos theory is that of time-bound dissipative structures, interacting with their open environment at far-from-equilibrium conditions, and transforming themselves from disorder to order through bifurcation. The role of strange or chaotic attractors is highlighted in the process. The first appendix gives background information in terms of the methodology. The second is the heart of the data upon which the thesis draws. That is, the second appendix outlines the case studies of the participants. Most are short summaries, but the final one is a detailed study, tracing the progress of the design and development of a subject in distance education.

Population dynamics of the infaunal bivalve, Soletellina alba

The population dynamics of the infaunal bivalve Soletellina alba was investigated at three sites situated within close proximity to the mouth of the Hopkins River estuary. The initial study design was planned to examine the importance of winter flooding to the persistence of this bivalve mollusc within the Hopkins estuary, since mass mortalities have been observed during previous years coincident with periods of winter flooding. Unfortunately, the climatic conditions experienced during this study were atypical compared to the long-term average, so detailed sampling was limited to two, unanticipated, non-flood years rather than two, highly anticipated, flood years. This hampered my ability to conduct complete tests of the importance of winter flooding. Patterns of river discharge and the frequency and duration of mouth opening and closing differed greatly from that expected. Unexpectedly, periods of mouth closure were not always associated with periods of minimal river discharge; low salinities were another unexpected result during an extended period of mouth closure during 1998. As expected, salinities varied considerably with increasing water depth when the estuary mouth was open. Mouth closure lead to salinities becoming more uniform between water depths but hypoxic and anoxic conditions became evident via stratification in the water column at 1 m below the Australian Height Datum (AHD). Other than trends associated with increased water depth, significant variation was not evident between measurements of salinity taken from three sites within close proximity of the estuary mouth (approximately 500 m), or during changes in tide. The most pertinent anomaly was the absence of winter flooding. The distribution and abundance of juvenile and adult S. alba was variable across all Dates, Sites and Channel elevations (i.e. water depths) sampled during this study. An experimental test comparing the recruitment of juveniles at different channel elevations and in sediments of varying particle size was conducted during an exceptionally successful period of recruitment during 1999. The results of these tests showed that recruitment was greatest at the shallowest channel elevation used, and there was little evidence that sediment particle size influenced recruitment. In contrast to 1999, recruitment during 1997 or 1998 was extremely poor. Growth rates were monitored using tagged individuals held in caged and uncaged plots, which revealed that growth was highly variable among individuals, but not between Sites. These tests also revealed that growth was negligible during the colder, winter months, and that the fastest growing individuals were capable of growing 0.2 mm/day. Mixed results were obtained for tests of potential cage artifacts and the influence of handling. Caging and differing amounts of handling did not appear to influence growth, but there was evidence that cages and handling influenced bivalve condition and number of mortalities. These direct tests appeared to be the most appropriate method for determining growth rates of this species, since attempts to analyse length-frequency data were made difficult by the apparent convergence of cohorts, and shell aging is difficult due to the thin, fragile nature of the shell. As expected, mass mortalities were observed during the flood of 1996, but not during the two non-flood years of 1997 and 1998. There were, however, some considerable declines in abundances at some channel elevations during the two non-flood years. However, these declines were attributable to the complete disappearance of individuals, rather than the sudden presence of numerous, recently dead individuals that typify observed declines during winter flooding. The complete disappearance of individuals suggest that S. alba may be capable of post-settlement emigration, or that they were consumed by an unknown predator. Salinity tolerance tests showed that bivalves exposed to low salinities (≤6 ppt), exhibited poorer condition and took longer to re-burrow into sediments than those exposed to greater salinities (≥14 ppt), while death of bivalves exposed to salinities ≤1 ppt occurred after 8 days of exposure. These tests provide evidence that low salinities are probably the principal cause of mass mortalities during winter flooding, although the interaction between salinity, temperature and turbidity also deserve consideration. The results of this study indicate that certain aspects of winter flooding, especially salinity, are responsible for the mass mortalities of S. alba rather than the result of a short-lived life history. I hypothesise that the survival of very young juveniles (between 0.5 and 1 mm shell length) and rapid growth rates are important features of the life history of S. alba that explain its successful persistence within the Hopkins River estuary. The rapid rates of growth suggest that it may be possible for juveniles that survive winter flooding to grow, reach sexual maturity, and reproduce before the onset of the next flood event. Unfortunately, the increased survivorship of juveniles during periods of winter flooding was not demonstrated by this study because of the absence of winter flooding and also relatively poor recruitment. It is highly likely that this species is capable of completing it entire life cycle within the estuary since the absence of other nearby populations, together with periods of mouth closure, are likely to greatly limit the potential contribution made by larvae entering from the surrounding marine environment. This study has added considerably to our knowledge of how infauna cope with life in the intermittently closing estuaries that typify semi-arid coastlines in the Southern Hemisphere.

Vegetarianism in Seventh-day Adventist home economics classes : an exploration of the issue

The practice of excluding meat from Adventist schools is at odds with the practice of many Adventists, and the Church which, while recommending vegetarianism, does not require it. The study investigates vegetarianism and explores the origin and aims of home economics, education and Seventh-day Adventism. These components were considered according to the three cognitive interests of the philosopher Jurgen Habermas.

Obesity prevention in the family day care setting : impact of the romp & chomp intervention on opportunities for children's physical activity and healthy eating

Background The Romp & Chomp intervention reduced the prevalence of overweight/obesity in pre-school children in Geelong, Victoria, Australia through an intervention promoting healthy eating and active play in early childhood settings. This study aims to determine if the intervention successfully created more health promoting family day care (FDC) environments.
Methods The evaluation had a cross-sectional, quasi-experimental design with the intervention FDC service in Geelong and a comparison sample from 17 FDC services across Victoria. A 45-item questionnaire capturing nutrition- and physical activity-related aspects of the policy, socio-cultural and physical environments of the FDC service was completed by FDC care providers (in 2008) in the intervention (n = 28) and comparison (n = 223) samples.
Results Select results showed intervention children spent less time in screen-based activities (P = 0.03), organized active play (P < 0.001) and free inside play (P = 0.03) than comparison children. There were more rules related to healthy eating (P < 0.001), more care provider practices that supported children’s positive meal experiences (P < 0.001), fewer unhealthy food items allowed (P = 0.05), higher odds of staff being trained in nutrition (P = 0.04) and physical activity (P < 0.001), lower odds of having set minimum times for outside (P < 0.001) and organized (P = 0.01) active play, and of rewarding children with food (P < 0.001).
Conclusions Romp & Chomp improved the FDC service to one that discourages sedentary behaviours and promotes opportunities for children to eat nutritious foods. Ongoing investment to increase children’s physical activity within the setting and improving the capacity and health literacy of care providers is required to extend and sustain the improvements.

Does the prescriptive lifestyle of Seventh-Day Adventists provide 'immunity' from the secular effects of changes in BMI?

Objective: To examine the effect of Seventh-day Adventist (SDA) membership on ‘immunity’ to the secular effects of changes in BMI.

Design: Three independent, cross-sectional, screening surveys conducted by Sydney Adventist Hospital in 1976, 1986 and 1988 and a survey conducted among residents of Melbourne in 2006.

Subjects: Two hundred and fifty-two SDA and 464 non-SDA in 1976; 166 SDA and 291 non-SDA in 1986; 120 SDA and 300-non SDA in 1988; and 251 SDA and 294 non-SDA in 2006.

Measurements: Height and weight measured by hospital staff in 1976, 1986 and 1988; self-reported by respondents in 2006.

Results: The mean BMI of non-SDA men increased between 1986 and 2006 (P < 0·001) but did not change for SDA men or non-SDA women. Despite small increases in SDA women’s mean BMI (P = 0·030) between 1988 and 2006, this was no different to that of SDA men and non-SDA women in 2006. The diet and eating patterns of SDA men and women were more ‘prudent’ than those of non-SDA men and women, including more fruit, vegetables, grains, nuts and legumes, and less alcohol, meat, sweetened drinks and coffee. Many of these factors were found to be predictors of lower BMI.

Conclusion: The ‘prudent’ dietary and lifestyle prescriptions of SDA men appear to have ‘immunised’ them to the secular effects of changes that occurred among non-SDA men’s BMI. The dietary and lifestyle trends of SDA women did not reflect the increase in their BMI observed in 2006.

Evaluating the outcomes of adolescent day programs in an Australian child and adolescent mental health service

Adolescent day programs (ADPs) are an increasingly used approach to treating adolescents with mental health issues. However, there is a dearth of studies empirically examining the outcomes of adolescent day programs. This study retrospectively examined the mental health functioning of 84 adolescents, pre- and post-treatment, who in addition to their ongoing outpatient treatment had participated in an ADP during a five-year period. Their functioning was compared to matched adolescents who participated only in outpatient treatment during the same time period. Statistical and clinical examinations revealed the reported outcomes following ADP treatment were at least comparable, and sometimes significantly better, when compared to the reported outcomes following outpatient treatment excluding ADP involvement. This study, while having some methodological shortcomings, provides some evidence for the efficacy of ADPs.

A comparison of the classification of disparate malware collected in different time periods

It has been argued that an anti-virus strategy based on malware collected at a certain date, will not work at a later date because malware evolves rapidly and an anti-virus engine is faced with a completely new type of executable not as amenable to detection as the first was. In this paper, we test this idea by collecting two sets of malware, the first from 2002 to 2007, the second from 2009 to 2010 to determine how well the anti-virus strategy we developed based on the earlier set [14] will do on the later set. This anti-virus strategy integrates dynamic and static features extracted from the executables to classify malware by distinguishing between families. The resulting classification accuracies are very close for both datasets, with a difference of only 5.4%, the older malware being more accurately classified than the newer malware. This leads us to conjecture that current anti-virus strategies can indeed be modified to deal effectively with new malware.

Building the capacity of family day care educators to promote children’s social and emotional wellbeing : an exploratory cluster randomised controlled trial

Background: Childhood mental health problems are highly prevalent, experienced by one in five children living in socioeconomically disadvantaged families. Although childcare settings, including family day care are ideal to promote children’s social and emotional wellbeing at a population level in a sustainable way, family day care educators receive limited training in promoting children’s mental health. This study is an exploratory wait-list control cluster randomised controlled trial to test the appropriateness, acceptability, cost, and effectiveness of “Thrive,” an intervention program to build the capacity of family day care educators to promote children’s social and emotional wellbeing. Thrive aims to increase educators’ knowledge, confidence and skills in promoting children’s social and emotional wellbeing.
Methods/Design: This study involves one family day care organisation based in a low socioeconomic area of Melbourne. All family day care educators (term used for registered carers who provide care for children for financial reimbursement in the carers own home) are eligible to participate in the study. The clusters for randomisation will be the fieldworkers (n = 5) who each supervise 10-15 educators. The intervention group (field workers and educators) will participate in a variety of intervention activities over 12 months, including workshops; activity exchanges with other educators; and focused discussion about children’s social and emotional wellbeing during field worker visits. The control group will continue with their normal work practice. The intervention will be delivered to the intervention group and then to the control group after a time delay of 15 months post intervention commencement. A baseline survey will be conducted with all consenting educators and field workers (n = ~70) assessing outcomes at the cluster and individual level. The survey will also be administered at one month, six months and 12 months post-intervention commencement. The survey consists of questions measuring perceived levels of knowledge, confidence and skills in promoting children’s social and emotional wellbeing. As much of this intervention will be delivered by field workers, field worker-family day care educator relationships are key to its success and thus supervisor support will also be measured. All educators will also have an in-home quality of care assessment at baseline, one month, six months and 12 months post-intervention commencement. Process evaluation will occur at one month, six months and 12 months post-intervention commencement. Information regarding intervention fidelity and economics will also be assessed in the survey.
Discussion: A capacity building intervention in child mental health promotion for family day care is an essential contribution to research, policy and practice. This initiative is the first internationally, and essential in building an evidence base of interventions in this extremely policy-timely setting.

Process and impact evaluation of the romp & chomp obesity prevention intervention in early childhood settings : lessons learned from implementation in preschools and long day care settings

Background: The Romp & Chomp controlled trial, which aimed to prevent obesity in preschool Australian children, was recently found to reduce the prevalence of childhood overweight and obesity and improve children’s dietary patterns. The intervention focused on capacity building and policy implementation within various early childhood settings. This paper reports on the process and impact evaluation of this trial and the lessons learned from this complex community intervention.
Methods: Process data was collected throughout and audits capturing nutrition and physical activity-related environments and practices were completed postintervention by directors of Long Day Care (LDC) centers (n = 10) and preschools (n = 41) in intervention and comparison (n = 161 LDC and n = 347 preschool) groups.
Results: The environmental audits demonstrated positive impacts in both settings on policy, nutrition, physical activity opportunities, and staff capacity and practices, although results varied across settings and were more substantial in the preschool settings. Important lessons were learned in relation to implementation of such community-based interventions, including the significant barriers to implementing health-promotion interventions in early childhood settings, lack of engagement of for-profit LDC centers in the evaluation, and an inability to attribute direct intervention impacts when the intervention components were delivered as part of a health-promotion package integrated with other programs.
Conclusions: These results provide confidence that obesity prevention interventions in children’s settings can be effective; however, significant efforts must be directed toward developing context-specific strategies that invest in policies, capacity building, staff support, and parent engagement. Recognition by funders and reviewers of the difficulties involved in implementing and evaluating such complex interventions is also critical to strengthening the evidence base on the effectiveness of such public health approaches to obesity prevention.

"I don't eat a hamburger and large chips every day!" A qualitative study of the impact of public health messages about obesity on obese adults

Background
We are a society that is fixated on the health consequences of 'being fat'. Public health agencies play an important role in 'alerting' people about the risks that obesity poses both to individuals and to the broader society. Quantitative studies suggest people comprehend the physical health risks involved but underestimate their own risk because they do not recognise that they are obese.

Methods
This qualitative study seeks to expand on existing research by exploring obese individuals' perceptions of public health messages about risk, how they apply these messages to themselves and how their personal and social contexts and experiences may influence these perceptions. The study uses in depth interviews with a community sample of 142 obese individuals. A constant comparative method was employed to analyse the data.

Results
Personal and contextual factors influenced the ways in which individuals interpreted and applied public health messages, including their own health and wellbeing and perceptions of stigma. Individuals felt that messages were overly focused on the physical rather than emotional health consequences of obesity. Many described feeling stigmatised and blamed by the simplicity of messages and the lack of realistic solutions. Participants described the need for messages that convey the risks associated with obesity while minimising possible stigmatisation of obese individuals. This included ensuring that messages recognise the complexity of obesity and focus on encouraging healthy behaviours for individuals of all sizes.

Conclusion
This study is the first step in exploring the ways in which we understand how public health messages about obesity resonate with obese individuals in Australia. However, much more research - both qualitative and quantitative - is needed to enhance understanding of the impact of obesity messages on individuals.

A comparison of the classification of disparate malware collected in different time periods

It has been argued that an anti-virus strategy based on malware collected at a certain date, will not work at a later date because malware evolves rapidly and an anti-virus engine is then faced with a completely new type of executable not as amenable to detection as the first was.

In this paper, we test this idea by collecting two sets of malware, the first from 2002 to 2007, the second from 2009 to 2010 to determine how well the anti-virus strategy we developed based on the earlier set [18] will do on the later set. This anti-virus strategy integrates dynamic and static features extracted from the executables to classify malware by distinguishing between families. We also perform another test, to investigate the same idea whereby we accumulate all the malware executables in the old and new dataset, separately, and apply a malware versus cleanware classification.

The resulting classification accuracies are very close for both datasets, with a difference of approximately 5.4% for both experiments, the older malware being more accurately classified than the newer malware. This leads us to conjecture that current anti-virus strategies can indeed be modified to deal effectively with new malware.