Melbourne Festival review: Vertical Influences' freewheeling dancers skate at breathtaking speeds

A theatre, gallery or concert hall – yes. But an ice rink? This is not a traditional venue for a Melbourne Festival performance. Under the team flags and beyond the trophy cases for competitive hockey and ice-skating, Vertical Influences features two works performed by five performers on skates.

Descriptions of rajid egg cases from southeastern Australian waters

Egg cases from nine skate species occurring in Tasmanian waters were examined and measured. A species-specific identification key is provided for eight of these species. The key was developed primarily from fresh egg cases dissected from the oviduct, although specimens collected from the ocean floor or found dried on the beach were also used to test the key. Egg cases for the ninth species could not be included because the only egg case pair recovered was partially fomled. A diagnosis of the posterior end of this egg case is provided.

Aspects of the life history of skates from southeastern Australia

The age and growth, reproduction and diet of several skate species in south-east Australia were studied. From studying these life history characteristics it was determined that skates have a relatively low productivity and may therefore be at risk of local extinction if increasingly exploited without appropriate management.

Urea-based osmoregulation in the developing embryo of oviparous cartilaginous fish (Callorhinchus milii) : contribution of the extraembryonic yolk sac during the early developmental period

Marine cartilaginous fish retain a high concentration of urea to maintain the plasma slightly hyperosmotic to the surrounding seawater. In adult fish, urea is produced by hepatic and extrahepatic ornithine urea cycles (OUCs). However, little is known about the urea retention mechanism in developing cartilaginous fish embryos. In order to address the question as to the mechanism of urea-based osmoregulation in developing embryos, the present study examined the gene expression profiles of OUC enzymes in oviparous holocephalan elephant fish (Callorhinchus milii) embryos. We found that the yolk sac membrane (YSM) makes an important contribution to the ureosmotic strategy of the early embryonic period. The expression of OUC enzyme genes was detectable in the embryonic body from at least stage 28, and increased markedly during development to hatching, which is most probably due to growth of the liver. During the early developmental period, however, the expression of OUC enzyme genes was not prominent in the embryonic body. Meanwhile, we found that the mRNA expression of OUC enzymes was detected in the extra-embryonic YSM; the mRNA expression of cmcpsIII in the YSM was much higher than that in the embryonic body during stages 28-31. Significant levels of enzyme activity and the existence of mitochondrial-type cmgs1 transcripts in the YSM supported the mRNA findings. We also found that the cmcpsIII transcript is localized in the vascularized inner layer of the YSM. Taken together, our findings demonstrate for the first time that the YSM is involved in urea-based osmoregulation during the early to mid phase of development in oviparous cartilaginous fish.

Construct validity of the pictorial scale of perceived movement skill competence

Objectives: The Pictorial Scale of Perceived Movement Skill Competence (PMSC) assesses young children's perceptions of movement skill competence: 12 perceived Fundamental Movement skills (FMS; based on the Test of Gross Motor Development 2nd edition TGMD-2) and six Active Play activities (e.g. cycling). The main study purpose was to assess whether children's movement perception scores fit within the imposed constructs of Active Play and FMS by testing the latent structure and construct validity of the PMSC.

Design: Construct validation study.

Methods: Participants were part of the Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT). The latent structure of the PMSC responses was tested through confirmatory factor analysis (CFA) and Bayesian Structural Equation Modeling (BSEM). Internal consistency was conducted using polychoric correlation-based alphas.

Results: The 303 children (boys 53.1%, n = 161) were aged 4-5 years (M = 4.7, SD = 0.46). The final model had an 18 item 3-factor solution with good fit indices (using CFA and BSEM). Factors were: Active Play (Bike, Board Paddle, Climb, Skate/Blade, Scooter, and Swim), Object Control - Hand Skills (Bounce, Catch, Hit, Throw), and FMS skills with a leg action (Gallop, Hop, Jump, Leap, Run, Step Slide, Kick, Roll). Alpha reliability values were: Active Play (0.78), Object Control-Hand Skills (0.76) and FMS-Dynamic Leg (0.84).

Conclusion: Young children can distinguish between movement perceptions. The factors reflect the hypothesized structure in terms of FMS being distinguished from Active Play. Further research should investigate how and if these constructs change in children over time.

Children impacted by parental substance abuse: an evaluation of the supporting kids and their environment program

The deleterious impact of parental substance abuse on child development and family functioning is well established. However, evaluations of interventions designed to ameliorate such impacts are very limited. This paper presents the results of a service evaluation using a pre-post design of the Supporting Kids And Their Environment (SKATE) program; a child-focused group program run by Glastonbury Community Services from 2006 to 2010 in the Geelong region of Victoria, Australia. The intervention was an 8-week psycho-educative model that used family-based techniques. Outcomes are reported for child behavior problems, assessed on the Child Behavior Checklist, and family functioning, assessed on the Family Support Scale. A total of 89 children and families within 13 intervention groups were recruited via adult Drug and Alcohol Services (Mean age = 10.4 years; SD = 2.4). Results suggest reductions in emotional and behavioral problems in children as well as improving family functioning with small to moderate effect sizes after children’s participation in the SKATE program compared to pre-test. These preliminary findings suggest that children whose parents are substance abusing are a high-risk group but they may benefit from targeted intervention programs that are well integrated with the adult drug treatment system. Such interventions warrant further development and evaluation.

Morphological and molecular investigations of the holocephalan elephant fish nephron: the existence of a countercurrent-like configuration and two separate diluting segments in the distal tubule

In marine cartilaginous fish, reabsorption of filtered urea by the kidney is essential for retaining a large amount of urea in their body. However, the mechanism for urea reabsorption is poorly understood due to the complexity of the kidney. To address this problem, we focused on elephant fish (Callorhinchus milii) for which a genome database is available, and conducted molecular mapping of membrane transporters along the different segments of the nephron. Basically, the nephron architecture of elephant fish was similar to that described for elasmobranch nephrons, but some unique features were observed. The late distal tubule (LDT), which corresponded to the fourth loop of the nephron, ran straight near the renal corpuscle, while it was convoluted around the tip of the loop. The ascending and descending limbs of the straight portion were closely apposed to each other and were arranged in a countercurrent fashion. The convoluted portion of LDT was tightly packed and enveloped by the larger convolution of the second loop that originated from the same renal corpuscle. In situ hybridization analysis demonstrated that co-localization of Na(+),K(+),2Cl(-) cotransporter 2 and Na(+)/K(+)-ATPase α1 subunit was observed in the early distal tubule and the posterior part of LDT, indicating the existence of two separate diluting segments. The diluting segments most likely facilitate NaCl absorption and thereby water reabsorption to elevate urea concentration in the filtrate, and subsequently contribute to efficient urea reabsorption in the final segment of the nephron, the collecting tubule, where urea transporter-1 was intensely localized.

Adolescents' ratings of features of parks that encourage park visitation and physical activity

BACKGROUND: The neighbourhood environment such as the availability of parks are a key, but under-researched, influence on adolescents' physical activity. In addition to overall physical activity levels, park-based physical activity and park visitation is low in this age group. Thus, it is critical to identify park features that may encourage or discourage adolescents from visiting parks. This study used a novel methodology to identify key physical characteristics of parks that are perceived to be important for park visitation and park-based physical activity among adolescents.

METHODS: Four secondary schools located in low, mid and high socio-economic status areas of Victoria, Australia were recruited. Using a purpose-built computer application, students in years 8-10 were presented with 44 original photographic images of park features. Participants rated each image (range 1-10) on how likely the feature would be to encourage them to visit a park and to engage in park-based physical activity, and placed symbols ('thumbs up'/'thumbs down') on aspects of the image that had a positive or negative influence on their ratings.

RESULTS: Participants (n = 99) had a mean age of 13.3 years (SD = 0.87) and 53% were female. Overall, the top three rated images prompting park visitation by adolescents were: a long steep slide, a flying fox and a table tennis table. These first two features were also reported as being likely to promote physical activity in the park. Differences in ratings were observed for boys and girls. The images that received the greatest number of "thumbs-up" symbols included large swings and slides, table tennis tables, no-smoking signs, flying foxes and BMX tracks. The images that received the greatest number of "thumbs-down" symbols included signage about rules, graffiti, toilets, concrete steps, and skate bowls.

CONCLUSION: Physically challenging play equipment is likely to encourage adolescents to visit and be active in parks. Rules, graffiti, toilets and skate bowls may discourage visitation. It is important for park designers, planners and policy makers to consider adolescents' views of what park design features are important so that parks are created that support and encourage visitation and optimise levels of physical activity when in the park.