The emergence and use of diagramming in system dynamics: a critical account

The paper reviews the leading diagramming methods employed in system dynamics to communicate the contents of models. The main ideas and historical development of the field are first outlined. Two diagramming methods—causal loop diagrams (CLDs) and stock/flow diagrams (SFDs)—are then described and their advantages and limitations discussed. A set of broad research directions is then outlined. These concern: the abilities of different diagrams to communicate different ideas, the role that diagrams have in group model building, and the question of whether diagrams can be an adequate substitute for simulation modelling. The paper closes by suggesting that although diagrams alone are insufficient, they have many benefits. However, since these benefits have emerged only as ‘craft wisdom’, a more rigorous programme of research into the diagrams' respective attributes is called for.

An assessment of the prebiotic potential of single and blended substrates in anaerobic in vitro batch culture fermentations using canine faecal samples as inocula

Previously, using an in vitro static batch culture system, it was found that rice bran (RB), inulin, fibersol, mannanoligosaccharides (MOS), larch arabinogalactan and citrus pectin elicited prebiotic effects (in terms of increased numbers of bifidobacteria and lactic acid bacteria) on the faecal microbiota of a dog. The aim of the present study was to confirm the prebiotic potential of each individual substrate using multiple faecal donors, as well as assessing the prebiotic potential of 15 substrate blends made from them. Anaerobic static and stirred, pH-controlled batch culture systems inoculated with faecal samples from healthy dogs were used for this purpose. Fluorescence in situ hybridization (FISH) analysis using seven oligonucleotide probes targeting selected bacterial groups and DAPI (total bacteria) was used to monitor bacterial populations during fermentation runs. High-performance liquid chromatography was used to measure butyrate produced as a result of bacterial fermentation of the substrates. RB and a MOS/RB blend (1:1, w/w) were shown to elicit prebiotic and butyrogenic effects on the canine microbiota in static batch culture fermentations. Further testing of these substrates in stirred, pH-controlled batch culture fermentation systems confirmed the prebiotic and butyrogenic effects of MOS/RB, with no enhancement of Clostridium clusters I and II and Escherichia coli populations.

`I feel enlightened now, but...`: the limits to the pedagogic translation of critical social discourses in physical education

The emancipatory goal that underpins critical theories of teaching and learning is built on a theory of rational self-determination. In the context of physical education, critical educators believe that through a process of enlightenment teachers can recognize and transform elements of injustice and inequality that exist, albeit unwittingly, in their practice. However, despite the broad appeal of this orientation there are relatively few empirical accounts of how theories of enlightenment manifest themselves in the practice of emancipation. Propelled by the lacuna that clearly exists between critical theory and critical practice, this paper reports on the introduction of critical social discourses to a preservice PE program. It uses a case study methodology to report on two student-teachers' engagement with a range of critical social discourses during a year-long PE unit. The paper discusses some of the ways these students engaged with the theory and practice of a critical orientation for teaching and learning in physical education. Aspects of their experiences are then interpreted through Fay's (1987) critical but postmodern "limits to change" thesis. The paper concludes with tempered optimism about the potential for critical social discourses to guide preservice teachers in practical ways.

On- and off-campus engineering student usage of a computer conferencing system

This article reports on the introduction of a computer-conferencing component into a first-year study unit in technology management at Deakin University, Australia. It was found that significant variations in computer usage were correlated to student study mode, including source of computer access, source of Internet access, hours-per-week computer usage, regular use of e-mail, regular use of the Internet, number of times the conference was accessed, use of computers for games, and use of computers for learning. Other moderate differences were also noted. Following exposure to the computer conference, on-campus students were more likely to agree that computers could assist their learning, and off-campus students were less likely to agree that learning from computers would be better than classes/lectures.

Absolute freedom and major structural change

Comments on the contribution of philosopher Slavoj Zizek to the reception of the works of psychoanalyst Jacques Lacan in universities. Analysis of philosophy, religion, politics and society; Notion of an act of absolute freedom; Consequences of an act.

Pharmaceutical benefits in Australia and Sweden: welfare policy and the cost of prescription drugs

Pharmaceutical benefits provide a stable framework within which consumers, prescribers, suppliers, pharmacists and other actors undertake transactions. The state in effect delivers a good that enhances individual autonomy. A major reason for the legitimacy enjoyed by pharmaceutical benefits in both Australia and Sweden is that these programs have strong attributes of universalism (rather than targeting). Sweden's predominantly public health system allows greater scope for pharmaceutical policy innovation. Australia's Pharmaceutical Benefits Scheme (PBS), while historically resilient and effective, is now wedged precariously between traditional considerations of equity and public health on the one hand, and constant pressure for increased marketisation on the other.

Knowledge about folate and the contribution of nutrient supplements to the intake of folic acid and vitamin B12 in Australian adults in 1995 and 1996

The present paper reports knowledge about folate and the contribution of supplements to the intake of folic acid and vitamin B12 in Australian adults during 1995 and 1996. Data were obtained from two population survey monitor surveys conducted in a sample of 5422 adults in 1995-96. The surveys were designed to complement food intake data from the 1995 National Nutrition Survey and to provide an estimate of total folate intake prior to the implementation of voluntary fortification of foods with folic acid. The proportion with knowledge about folate increased with education level and socioeconomic status and was greater in women than men. It was also greater in those who were married, and in those residing in Western Australia and the Australian Capital Territory than in other states and territories. Five per cent of men and 10% of women had taken a supplement containing folio acid on the previous day. The equivalent figures for vitamin B12 were 7.5% for men and 12.5% for women. On average, intake of folic acid from supplements was 11 micro g per day for men and 28 micro g per day for women and intake of vitamin B12 was 2.6 micro g per day for men and 4.5 micro g per day for women. For individuals who consumed a supplement containing folic acid on the day before the survey the median folic acid contribution was 200 micro g. In 1995 and 1996 only one in two adult Australians had heard of folate and only one in ten women of child-bearing age had taken a supplement containing folic acid.

Amino acids and endurance exercise

Provides information on a study which examined the role of amino acids during endurance exercise and the implications for sports nutrition and performance. Description of amino acid utilization during exercise; Function of glutamine; Cardiovascular function of L-arginine.

Pre-exercise nutritional strategies: effects on metabolism and performance

The goals of pre-exercise nutritional strategies are to optimise the availability of carbohydrate (CHO) and fluid. Ingestion of CHO 3-4 hr prior to exercise can increase liver and muscle glycogen stores and has been associated with enhanced endurance exercise performance. The metabolic effects of CHO ingestion persist for at least 6 hr. Although an increase in plasma insulin following CHO ingestion in the hour prior to exercise inhibits lipolysis and liver glucose output, and can lead to transient hypoglycemia during subsequent exercise, there is no convincing evidence that this is always associated with impaired exercise performance. Having said that, individual experience should inform individual practice. Interventions to increase plasma FFA availability prior to exercise have been shown to reduce CHO utilisation during exercise, but do not appear to have major ergogenic benefits. It is more difficult to hyperhydrate prior to exercise and although there has been interest in glycerol ingestion, to date research results have been equivocal. At the very least, athletes should ensure euhydration prior to exercise.

Diet and hypertension in the Asia-pacific region : a brief review

In this paper, the possible reasons for the prevalence of hypertension in the Asia–Pacific region are examined, along with its likely dietary, nutritional and sociocultural causes. This brief survey indicates the need for more comprehensive blood pressure monitoring and surveillance throughout the region. Findings from research conducted in the region and elsewhere suggest that a variety of aetiological factors predict the occurrence of hypertension, most of which are similar to those observed in western populations. However, several lines of research suggest that obesity, abdominal obesity and a number of dietary constituents, in addition to salt, may play relatively greater roles than in western populations. It is argued that hypertension may be prevented via a combination of individual, community and governmental approaches which promote social capital, environmentally sustainable food production and the public health.

Psychological correlates of perception of sexual intent in women

In a sample of 183 men and 186 women, the authors assessed (a) the relative contributions of gender and level of nonverbal social cues to the perception of a female actor's sexual intent during a videotaped social interaction with a man and (b) the association between those variables and personality traits implicated in faulty sexual-information processing. The authors assessed those variables while the participants viewed 1 of 3 film segments depicting a female-male interaction. The authors experimentally manipulated eye contact, touch, physical proximity, and female clothing. At all levels of those nonverbal cues, the men perceived more sexual intent in the female actor than did the women. The perception of the female actor's sexual intent increased as the nonverbal cues in the film segments were magnified: Both actors displayed more eye contact, touch, and physical proximity, and the female actor wore more revealing clothing. Relative to the women, the men demonstrated greater sexual preoccupation and reduced sociosexual effectiveness, variables associated with inferring greater sexual intent in the female actor.