Predators select against high growth rates and risk-taking behaviour in domestic trout populations

Domesticated (farm) salmonid fishes display an increased willingness to accept risk while foraging, and achieve high growth rates not observed in nature. Theory predicts that elevated growth rates in domestic salmonids will result in greater risk–taking to access abundant food, but low survival in the presence of predators. In replicated whole–lake experiments, we observed that domestic trout (selected for high growth rates) took greater risks while foraging and grew faster than a wild strain. However, survival consequences for greater growth rates depended upon the predation environment. Domestic trout experienced greater survival when risk was low, but lower survival when risk was high. This suggests that animals with high intrinsic growth rates are selected against in populations with abundant predators, explaining the absence of such phenotypes in nature. This is, to our knowledge, the first large–scale field experiment to directly test this theory and simultaneously quantify the initial invasibility of domestic salmonid strains that escape into the wild from aquaculture operations, and the ecological conditions affecting their survival.

Finding common ground: enhancing interaction between domestic and international students in higher education

A feature of Australian Higher Education over the last 10 years has been the increased numbers of international students. This feature has been perceived to have great potential for enhanced learning for all students – both international and domestic. Yet, student surveys and research clearly indicate that there is very little interaction occurring between domestic and international students. This article reports on a study that investigated the extent to which university teaching can promote interaction between students from diverse cultural and linguistic background. Using an innovative video-analysis methodology, the research found that academics engage in a variety of activities to encourage interaction between student groups. In order to assist academics in planning interaction, one of the main findings of the study was the development of ‘The Interaction for Learning Framework (ILF)’, that identifies key dimensions for curriculum design that can be used by academics to inform ways that they can enhance interaction between diverse student groups within teaching and learning contexts.

Problem gambling among international and domestic university students in Australia : who is at risk?

Young people are a high risk group for gambling problems and university (college) students fall into that category. Given the high accessibility of gambling in Australia and its association with entertainment, students from overseas countries, particularly those where gambling is restricted or illegal, may be particularly vulnerable. This study examines problem gambling and its correlates among international and domestic university students using a sample of 836 domestic students (286 males; 546 females); and 764 international students (369 males; 396 females) at three Australian universities. Our findings indicate that although most students gamble infrequently, around 5 % of students are problem gamblers, a proportion higher than that in the general adult population. Popular gambling choices include games known to be associated with risk (cards, horse races, sports betting, casino games, and gaming machines) as well as lotto/scratch tickets. Males are more likely to be problem gamblers than females, and almost 10 % of male international students could be classified as problem gamblers. Hierarchical regression analysis showed that male gender, international student status, financial stress, negative affect and frequency of gambling on sports, horses/dogs, table games, casino gaming machines, internet casino games and bingo all significantly predicted problem gambling. Results from this study could inform gambling-education programs in universities as they indicate which groups are more vulnerable and specify which games pose more risk of problem gambling.

Progression of cardiovascular and endocrine dysfunction in a rabbit model of obesity

In rabbits, mean arterial pressure (MAP) increases in response to fat feeding, but does not increase further with progressive weight gain. We documented the progression of adiposity and the alterations in endocrine/cardiovascular function in response to fat feeding in rabbits, to determine whether stabilization of MAP after 3 weeks could be explained by stabilization of neurohormonal factors. Rabbits were fed a control diet or high-fat diet for 9 weeks (n¼23). Fat feeding progressively increased body mass and adiposity. Heart rate (HR) was elevated by week 3 (15±3%) but changed little thereafter. The effects of fat feeding on MAP were dependent on baseline MAP and peaked at 3 weeks. From baseline, MAP p80mmHg, MAP had increased by 8.1±1.3, 4.7±1.7 and 5.6±1.2mmHg, respectively, 3, 6 and 9 weeks after commencing the high-fat diet, but by only 2.6±1.5, 3.0±1.7 and 3.9±1.4mmHg, respectively, in control rabbits. Fat feeding did not increase MAP from a baseline 480mmHg. Plasma concentrations of leptin and insulin increased during the first 3–6 weeks of fat feeding and then stabilized (increasing by 111±17% and 731±302% by week 9, respectively), coinciding with the pattern of changes in MAP and HR. Plasma total cholesterol, triglycerides, renin activity, aldosterone and atrial natriuretic peptide were not significantly altered by fat feeding. Given that the changes in plasma leptin and insulin mirrored the changes in MAP and HR, leptin and insulin may be important factors in the development of hypertensionand tachycardia in the rabbit model of obesity.

The continued importance of a feminist analysis: gendered inequalities visible through a critique of Howard government policy on domestic violence

This paper argues that feminist analyses remain crucial to any critical analysis of social policy. From the outset, it needs to be said that we are not suggesting that other critical analyses are less important, such as anti-racist analysis, for example (Dominelli 2002a, 2002b). We also acknowledge the significance of intersectionality theory which identifies the ways in which race and racism may compound gender inequality to shape experiences of oppression or privilege (Mullings & Schultz 2006; Weber 2006). Having said this, in this paper we argue that feminist analyses remain as important as ever, in challenging dominant patriarchal/capitalist discourse currently informing social policy in Australia.

As a counter discourse, feminism puts women’s experiences and the unequal relationships of patriarchy at the forefront of analysis, highlights gender inequalities entrenched in social institutions and policy, and draws attention to the organisation of society along gender specific lines and the inequalities resulting from the relegation of women to the private sphere (Dominelli 2002a).

Specifically, we will demonstrate that the Howard government’s policy responses to the issue of family violence have reflected a renewed attack on previous gains made by women, and exemplify a neo-liberal, neo-conservative approach to social policy that demands a critical feminist analysis. Given the recent federal election, it seems particularly timely to reassert the importance of a feminist analysis of social policy and to direct the attention of the new federal government towards reversing recent trends to de-politicise violence towards women.

The pace of life under artificial selection : personality, energy expenditure, and longevity are correlated in domestic dogs

The domestic dog has undergone extensive artificial selection resulting in an extreme diversity in body size, personality, life‐history, and metabolic traits among breeds. Here we tested whether proactive personalities (high levels of activity, boldness, and aggression) are related to a fast “pace of life” (high rates of growth, mortality, and energy expenditure). Data from the literature provide preliminary evidence that artificial selection on dogs (through domestication) generated variations in personality traits that are correlated with life histories and metabolism. We found that obedient (or docile, shy) breeds live longer than disobedient (or bold) ones and that aggressive breeds have higher energy needs than unaggressive ones. These correlations could result from either human preference for particular trait combinations or, more likely, correlated responses to artificial selection on personality. Our results suggest the existence of a general pace‐of‐life syndrome arising from the coevolution of personality, metabolic, and life‐history traits.

Commentary on Stuart et al. (2013): Domestic violence and interventions to reduce alcohol use

This study, reported by Gregory Stuart and colleagues, offers empirical evidence to support the hypothesis that perpetrators of domestic violence who receive a brief intervention to address alcohol use in addition to a 40-hour group batterer programme will not only consume fewer drinks (and on fewer days) than those who only receive the batterer programme, but will also be less likely to be aggressive and violent.Although these effects fade over time, these findings are significant in the context of an area in which the efficacy of many behaviour change programmes has yet to be demonstrated adequately [2], and in which there is a pressing need to develop more effective interventions.

Changing provocation law could legitimise lethal acts of domestic violence

The O'Farrell government must reconsider their recommendation to retain a restricted version of the controversial partial defence of provocation. The government has released a draft exposure bill recommending reform of a partial defence that has long attracted criticism and community concern. Under the proposed reform, the defence will be significantly restricted and will be renamed the "partial defence of extreme provocation".