The central-place territorial model does not apply to space-use by juvenile brook charr Salvelinus fontinalis in lakes

1. Territoriality is widely accepted as the mechanism responsible for density-dependent mortality, emigration, and 'self-thinning' of populations of juvenile salmonine fishes in streams. Numerous studies have focused on territoriality exclusively in stream (lotic) environments and thus have fostered a stereotyped view of juvenile salmonines as sedentary and territorial. We term this behavioural paradigm the central-place territorial model (CPTM).

2. We tested predictions characterizing the CPTM for young-of-the-year (YOY) brook charr (Salvelinus fontinalis) in two Canadian lakes to determine if territoriality may also potentially limit space and population size of brook charr in lakes.

3. Our findings were not consistent with the CPTM. Fish in both lakes were not central-place forages. Maximum displacement distance did not increase with body length as predicted by the general salmonine model of Grant and Kramer (1990). Net displacement distanced increased with the proportion of time spent moving. Aggressive frequency was greatest for fish which spent large proportions of time moving and did not defend from a central-place.

4. Fish in both lakes were rarely aggressive, highly active, and often moved back over the same areas. However, lake fish which migrated to a tributary stream had no net displacement (central-place foraging) illustrating the immediate effects of current on foraging tactics and space-use.

5. The effect of hydrodynamic environment (flowing vs. still water) on fish behaviour needs to be explicitly considered in future models of salmonine behaviour.

Drifting or walking? colonisation routes used by different instars and species of lotic, macroinvertebrate filter feeders

Many views of stream invertebrate populations centre on drift as the major route of larval dispersal, but few studies have presented unambiguous information about the role of drift. We present the results from an experiment designed to determine whether the major route of colonisation of substrata by hydropsychid larvae (commonly found in the drift) is by drifting directly onto substrata or by walking along the stream bottom. The experimental design contained four treatments: substrata open to drifters and walkers; fenced substrata open to drifters only; and two treatments open to drifters and walkers that provided forms of fence controls. Fifteen replicates of each treatment were set out at random locations within a riffle at each of three sites, with each site on a different river (the Little River, the Steavenson River and the Acheron River) in the Acheron River catchment. The experiment was run twice, once during autumn (April 1999) and once during early summer (January 2000). Both experiments were colonised by three species of hydropsychids, Asmicridea sp. AV1, and Smicrophylax sp. AV1 and AV2. We found that 2nd/3rd instars of Asmicridea sp. AV1 walked as well as drifted, whereas all others primarily drifted. No relation between numbers of recruits and water speed was found when substrata were open only to drifters, whereas substrata open also to walkers gained more recruits in faster flows. Additionally, larvae more frequently abandoned nets in slow than fast flows, indicating that drifting into unfavourable flow environments may result in mortality or redispersal of larvae. These findings demonstrate that, although drift is important, it is not necessarily the only method used by hydropsychids to colonise substrata. Larvae may have more capacity to choose substrata in fast flows when they colonise substrata by walking. Spot measures of hydropsychid distribution cannot distinguish between these explanations. The finding that walkers can sometimes comprise significant numbers of recruits raises the prospect that hydropsychids can be sourced locally and have not inevitably drifted in from upstream locations.

Wikis: collaborative virtual learning environments

Ward Cunningham used the word wiki (the Hawaiian word meaning quick) to name the collaborative tool he developed for use on the internet in 1994. Wikis are fully editable websites. Users can visit, read, re-organize and update the structure and content (text and pictures) of a wiki as they see fit. This functionality is called open editing (Leuf & Cunningham, 2001). All a user needs to edit and read a wiki, is a web browser. Consequently, the wiki has great potential for use as a collaborative virtual learning environment. Wikis abound on the internet. A well known wiki is Wikipedia an online collaborative encyclopaedia, where anybody can read, edit, re-organize and update the encyclopaedia content (Wikipedia, 2004).

Thermoregulation in young athletes exercising in hot environments.

Children are less efficient thermoregulators than are adults. During exercise, sweat evaporation is the most important physiological means of cooling the body. The sweat response in children, however, is less efficient than in adults, so children dissipate less heat though evaporative sweating and more through convection (the loss of heat through the skin) plus radiation. Children and adolescents with high levels of body fat and heavy builds are more susceptible to heat stress because they dissipate body heat less efficiently. Maintaining adequate hydration is crucial for preventing heat stress, Although water is often described as the best choice of fluid, studies on voluntary drinking habits and flavor preferences in children and adolescents suggest that greater consumption occurs when sports drinks are offered instead of water. Although a child's sweat contains less sodium and chloride than an adult's does, there appears to be no evidence that a child's performance improves when given beverages more diluted than those currently recommended for adults, More information is necessary to identify the optimal electrolyte and carbohydrate content of sports drinks for young athletes.

Family food environments as determinants of preschool-aged children`s eating behaviours: implications for obesity prevention policy. A review.

Children's eating behaviours are fundamental to their health. Dietary surveys indicate that children's food consumption is likely to promote a range of diet-related diseases, including overweight and obesity, which are associated with a range of psychosocial and physical disorders. With the prevalence of overweight and obesity rapidly increasing, opportunities for informed prevention have become a focus of strategy. Diet is recognised as important in the genesis of obesity. We present data that demonstrate that eating behaviours are likely to be established early in life and may be maintained into adulthood. We review literature that shows that children's eating behaviours are influenced by the family food environment. These findings suggest that the family environment should be considered in developing obesity prevention strategy for children, yet the current strategy focuses primarily on the school environment. Those factors in the family environment that appear to be important include: parental food preferences and beliefs, children's food exposure; role modelling; media exposure; and child-parent interactions around food. However, the existing data are based on small scale and unrepresentative US samples. At a population level, we have few insights regarding family food environments and consequently little information about how such environments influence children's eating behaviours and thus their risk for obesity. We suggest research that may promote a better understanding of the role of family food environments as determinants of children's eating behaviour, and consider the implications for obesity prevention in Australia. (Aust J Nutr Diet 2001;58:19-25)

The influence of object-image velocity change on perceived heading in minimal environments

When human observers move forward and rotate their eyes, a complex pattern of light flows across the retina. This pattern is referred to as retinal flow. A model has been proposed to explain how humans perceive their direction of self-movement (or heading) from (1) static depth, (2) direction of image motion, and (3) whether image velocity undergoes acceleration or deceleration (Wang & Cutting, 1999). However, findings from past research in which sparse or minimalist stimuli were used have suggested that not all of the information to which participants are sensitive is captured within the scope of this model. In particular it has been suggested that the magnitude or size of image velocity change may be of significance beyond simply whether image velocity could be categorized as speeding up (i.e., accelerating) or slowing down (i.e., decelerating). In two experiments, the influence of this factor on heading judgments under minimal conditions was investigated. Evidence was found in support of the idea that the rate of image velocity change can influence judgments of the direction of self-movement in minimalist conditions.

Speculative fictions for understanding global change environments: two thought experiments

The purpose of a thought experiment, as the term was used by quantum and relativity physicists in the early part of the twentieth century, was not prediction (as is the goal of classical experimental science), but more defensible representations of present ‘realities’. Speculative fictions, from Mary Shelley's Frankenstein to the Star Wars cinema saga, can be read as sociotechnical thought experiments that produce alternative representations of present circumstances and uncertainties, and anticipate and critique possible futures. In this essay I demonstrate how two examples of popular speculative fictions, Frank Herbert's Dune (1965) and Ursula Le Guin's The Telling (2000), function as thought experiments that problematise global transitions in their respective eras. I argue that critical readings of such stories can help us to anticipate, critique, and respond constructively to social and cultural changes and change environments within nation-states that constitute, and are constituted by, global change processes and their effects.

Contemporary learning environments: designing e-learning for education in the professions

Designing e-learning environments for quality professional education is a challenge for education designers, as the continuing practice of simply moving courses online can be surprisingly disabling. We argue that as universities strive to educate for excellence in professional practice, design approaches for the e-learning components must be conceptualized in a broader view of a contemporary learning environment involving integrated virtual and physical dimensions. These are comprehensively considered in an integrated way to facilitate learning experiences providing an emphasis on grounded practice. Our paper considers learning environments in the service of a broader understanding of a professional "practicum." In providing the more flexible, immediate and evolving virtual experiences, e-learning as a feature must take account of a range of education design considerations we model in a framework of elements. These are outlined, and broader issues are illuminated through a comparative case analysis of educational technology developments at Deakin University in the two professional fields of teaching and journalism. The Education Studies Online (ESO) project and the HOTcopy newsroom simulation project exemplify elements of the approach recommended in addressing the challenges of quality professional education. We highlight the generative role of the education designer in adopting an integrative and strategic stance, when creating such environments. Implications for the selection and use of various e-learning resources and corporate e-learning systems become evident as we highlight the dangers of a returning "instructional industrialism" as we risk allowing courses to "move online", rather than moving towards proposed features of contemporary learning environments.

Multisensory environments for leisure: promoting well-being in nursing home residents with dementia

Multisensory environments such as Snoezelen^® rooms are becoming increasingly popular in health care facilities for older individuals. There is limited reliable evidence of the benefits of such innovations, and the effect they have on residents, caregivers, and visitors in these facilities. This two-stage project examined how effective two types of multisensory environments were in improving the well-being of older individuals with dementia. The two multisensory environments were a Snoezelen room and a landscaped garden. These environments were compared to the experience of the normal living environment. The observed response of 24 residents with dementia in a nursing home was measured during time spent in the Snoezelen room, in the garden, and in the living room. In the second part of the project, face-to-face interviews were conducted with six caregivers and six visitors to obtain their responses to the multisensory environments. These interviews identified the components of the environments most used and enjoyed by residents and the ways in which they could be improved to maximize well-being.

Designing contemporary learning environments for excellence in public relations

Universities are striving to enhance the quality of the educational experience in the professions in response to external and internal pressures. The professional field of public relations (PR) is not immune to these forces. Previously, enhancements were often pursued through particular initiatives relating to curriculum, pedagogical or assessment redesign at the unit level. While such initiatives are valuable we argue for a strategic, integrated, programmatic approach. This requires the design of learning environments, with integrated virtual and physical dimensions, based on a relevant and meaningful curriculum, and student-centred approaches to learning. These learning environments enable quality learning in fields like public relations with diverse student cohorts studying on- and off-campus. The challenges involved in designing what we term ‘contemporary learning environments’ are illuminated through a case study of Deakin University’s Public Relations Program. Over the last three years redesigning PR online has led to changed curriculum, and pedagogical and assessment practices. We conclude by suggesting that a commitment to continuous quality improvement will be required to ensure the program’s learning environment remains relevant to the needs of students studying in the field.