Growth performance, feed efficiency and fatty acid composition of juvenile Murray cod, Maccullochella peelii peelii, fed graded levels of canola and linseed oil

n two independent experiments, the effects of dietary inclusion of canola and linseed oil were evaluated in juvenile Murray cod (Maccullochella peelii peelii, Mitchell) over a 112-day period. In each experiment, fish received one of five semi-purified diets in which the dietary fish oil was replaced with canola oil (Experiment A) or linseed oil (Experiment B) in graded increments of 25% (0–100%). Murray cod receiving the graded canola and linseed oil diets ranged in final weight from 112.7 ± 7.6 to 73.8 ± 9.9 g and 93.9 ± 3.6 to 74.6 ± 2.2 g, respectively, and exhibited a negative trend in growth as the inclusion level increased. The fatty acid composition of the fillet and liver were modified extensively to reflect the fatty acid composition of the respective diets. Levels of oleic acid (18:1 n-9) and linoleic acid (18:2 n-6) increased with each level of canola oil inclusion while levels of α-linolenic acid (18:3 n-3) increased with each level of linseed oil inclusion. The concentration of n-3 highly unsaturated fatty acids in the fillet and liver decreased as the amount of vegetable oil in the diets increased. It is shown that the replacement of fish oil with vegetable oils in low fish meal diets for Murray cod is possible to a limited extent. Moreover, this study reaffirms the suggestion for the need to conduct ingredient substitution studies for longer periods and where possible to base the conclusions on regression analysis in addition to anova.

Dispersal and recruitment of juvenile Red-capped Robins, Petroica goodenovii

Data on the dispersal and recruitment of juvenile birds following fledging are largely unreported for Australian birds. In this study, we investigated the short-distance dispersal of a sample of colour-banded, juvenile Red-capped Robins, Petroica goodenovii, in Terrick Terrick National Park, Victoria, Australia. Of 67 colour-banded juvenile birds that successfully reached independence during the 2000–01 breeding season, eight were recruited into the study area or adjacent areas for the following breeding season. A ninth bird was resighted in Gunbower State Forest, 36 km from where it was banded. This is the furthest recorded dispersal movement of a Red-capped Robin. Of 59 colour-banded juvenile birds that reached independence during the 2001–02 season, four remained within the study area for the remainder of the breeding season, but these birds were not present in the study area during the following breeding season. Juvenile birds that successfully reached independence and dispersed were heavier as nestlings, when controlled for age and date, than birds that disappeared (assumed dead) before reaching independence. Estimates of Red-capped Robin abundances within Terrick Terrick National Park were greater than those of nearby eucalypt woodlands, suggesting that the White Cypress-pine, Callitris glaucophylla, woodlands within the park offer good-quality habitat for Red-capped Robins and may be saturated with breeding territories. Thus, juveniles may be forced to establish breeding territories far from their natal territories. These results are discussed in relation to avenues for further research on juvenile dispersal in Australian birds and their conservation implications.

What`s the story? An exploration of narrative language abilities in male juvenile offenders

This paper is concerned with the narrative language (story telling) abilities of a group of juvenile offenders completing community-based court orders in Melbourne, Australia. A convenience sample of 30 male young offenders was compared with 50 male non-offenders attending government high schools in the same region of Melbourne. Participants provided an audiotaped description of a six-frame cartoon (the “Flowerpot Incident”). Samples were transcribed and subjected to story grammar analysis, to examine differences between groups regarding both structural and qualitative adequacy. Young offenders produced narratives which were significantly poorer than those of controls with respect to the presence and adequacy of the seven story grammar elements described by Stein and Glenn (In R. O. Freedle (Ed.), New Directions in Discourse Processing (pp. 53-120) 1979). Findings are discussed in relation to implications for investigative and evidentiary interviewing.

Virtual non-profit organisations: literary virtual communities in Russia

This paper is a study of one of the “unknown” segments of the Internet - non-profit ventures in the Russian language.Based on the understanding of the concept of virtual community we consider the family of free publishing literary websites. We discuss their experience to demonstrate their contribution not only to the national culture, but also to the creation of open and democratic society in the former communist world, and to new forms of literary life. Some of the innovative concepts, principles and practices, adopted on those sites may be of interest to the Internet developers and
communities worldwide.

Banding and radio-tracking juvenile powerful owls in Melbourne, Victoria : trials and tribulations

The Powerful Owl (Ninox strenua) is Australia's largest owl. Considering their large size they are a very cryptic species, with limited sexual dimorphism, silent fight and a highly camouflaged presence amongst secluded canopy vegetation. These features enable Powerful Owl presence to often go unnoticed and even for the trained eye, extremely difficult to study. Our research has focused on monitoring the behaviour of individual Powerful Owls in urban Melbourne, Australia.
The leg banding of Powerful Owls is a somewhat contentious issue in Australia and here we report on the suitability of different types of legs bands placed on the tarsus of juvenile Powerful Owls. There has been some debate over the band size that should be used and the consequent effects bands may pose for the owls as they mature. We also investigate the usefulness of bands as a technique to identify Powerful Owls once they have dispersed from the natal territory.
Radio-tracking juvenile Powerful Owls was also undertaken during this study, primarily to determine individual behaviour from post fledging until dispersal. This is the first study in Australia to attempt radio-tracking juvenile Powerful Owls and the results from this research highlight behavioural characteristics, mortality rates post fledging and dispersal movements for the twelve months post fledging.
Overall we found that aluminium legs bands are a useful tool for individual identification of juvenile Powerful Owls post fledgling, however, their presence is somewhat difficult to determine on mature adults as the tarsus feathers tend to cover the band and make vision from the ground difficult. Aluminium leg bands are also useful as an identification tool for deceased birds. Leather leg bands are more suitable than aluminium bands when attaching radio-transmitters as these provide more flexibility and can be removed by the owl if they become irritating.
Radio-tracking juvenile Powerful Owls provided invaluable information relating to juvenile behaviour and movements, showing that juveniles actually remain in territories adjacent to their natal territory for the twelve months post fledging. This information is vital for the successful conservation of this species, particularly in relation to habitat conservation and home-range modelling.

Oral language competence, social skills and high-risk boys : what are juvenile offenders trying to tell us?

A cross-sectional study examining the oral language abilities and social skills of male juvenile offenders is described. Fifty juvenile offenders and 50 non-offending controls completed measures of language processing and production, and measures of social skill and IQ. Information about type of offending, substance use histories and learning/literacy problems was also gathered.

Young offenders performed significantly worse on all language and social skill measures, but these differences could not be accounted for on the basis of IQ. Just over half of the young offenders were identified as language impaired. This subgroup was compared with non-language impaired offending peers on a range of variables. The findings have particular implications in the areas of early intervention for high-risk boys and investigative interviewing of juvenile offenders.