Exploration in the Canadian Rocky Mountains

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Evaluation and management implications of uncertainty in a multispecies size-structured model of population and community responses to fishing

1. Implementation of an ecosystem approach to fisheries requires advice on trade-offs among fished species and between fisheries yields and biodiversity or food web properties. However, the lack of explicit representation, analysis and consideration of uncertainty in most multispecies models has limited their application in analyses that could support management advice. 2. We assessed the consequences of parameter uncertainty by developing 78 125 multispecies size-structured fish community models, with all combinations of parameters drawn from ranges that spanned parameter values estimated from data and literature. This unfiltered ensemble was reduced to 188 plausible models, the filtered ensemble (FE), by screening outputs against fish abundance data and ecological principles such as requiring species' persistence. 3. Effects of parameter uncertainty on estimates of single-species management reference points for fishing mortality (FMSY, fishing mortality rate providing MSY, the maximum sustainable yield) and biomass (BMSY, biomass at MSY) were evaluated by calculating probability distributions of estimated reference points with the FE. There was a 50% probability that multispecies FMSY could be estimated to within ±25% of its actual value, and a 50% probability that BMSY could be estimated to within ±40% of its actual value. 4. Signal-to-noise ratio was assessed for four community indicators when mortality rates were reduced from current rates to FMSY. The slope of the community size spectrum showed the greatest signal-to-noise ratio, indicating that it would be the most responsive indicator to the change in fishing mortality F. Further, the power of an ongoing international monitoring survey to detect predicted responses of size spectrum slope was higher than for other size-based metrics. 5. Synthesis and applications: Application of the ensemble model approach allows explicit representation of parameter uncertainty and supports advice and management by (i) providing uncertainty intervals for management reference points, (ii) estimating working values of reference points that achieve a defined reduction in risk of not breaching the true reference point, (iii) estimating the responsiveness of population, community, food web and biodiversity indicators to changes in F, (iv) assessing the performance of indicators and monitoring programmes and (v) identifying priorities for data collection and changes to model structure to reduce uncertainty

Exploring the roles of academic, personal, and cultural demands and resources in immigrant students' motivation, engagement, and achievement

Background The present investigation applied the academic and cultural demands-resources (ACD-R) framework to better understand the academic development of immigrant high school students. Aims Analyses sought to test the hypothesized contribution of academic demands (e.g., learning-disrupted teaching) and resources (e.g., autonomy-supportive teaching), personal demands (e.g., fear of failure) and resources (e.g., adaptability), and cultural demands (e.g., discrimination) and resources (e.g., cultural confidence) in predicting motivation (self-efficacy, valuing)—and, in turn, the extent to which motivation predicted academic outcomes in the forms of engagement (persistence, non-attendance) and performance (achievement). Sample Drawing on PISA (2018) data, the sample comprised 4886 immigrant students: 3329 from Australia and 1557 from New Zealand. Method Confirmatory factor analysis (CFA) was first conducted to ascertain the psychometric properties of the study's measures and then the central analyses employed structural equation modelling (SEM) to test hypothesized paths. Results After demonstrating good CFA fit, SEM revealed that particularly salient (at p < 0.001) demand and resource predictors of motivation were: warmth-supportive teaching (positively), fear of failure (negatively), adaptability (positively), discrimination (negatively), cultural communication skills (positively), and cultural confidence (positively). Also, self-efficacy and valuing significantly predicted persistence (positively) and non-attendance (negatively), while self-efficacy also significantly predicted achievement (positively). Conclusions The hypothesized ACD-R process is a viable means to understand immigrant students’ academic experience and to offer some fruitful direction for supporting their academic development

The role of health demands, health resources, and adaptability in psychological strain and life satisfaction

The present study harnessed job demands-resources theory to identify key predictors of psychological strain (feeling overwhelmed by one's problems) and life satisfaction among a sample of 1060 adults randomly selected from the Australian electoral roll. The investigation sought to ascertain: (a) the relative contribution of health demands (e.g., inadequate health treatment) and health resources (e.g., access to helpful health-related information) in predicting psychological strain and life satisfaction, (b) the extent to which a recently proposed personal resource—adaptability—explained variance in wellbeing beyond individuals' health demands and resources, and (c) the role of psychological strain in predicting life satisfaction in the context of these demands and resources. Applying structural equation modelling we found that contextual health demands predicted greater psychological strain, individual health resources and adaptability both predicted lower psychological strain and greater life satisfaction, and psychological strain predicted lower life satisfaction. Notably, the adverse effects of health demands reduced significantly when health resources and adaptability were entered into the modelling. Taken together, the findings offer support for a health demands-resources framework that may be applied to better support individuals to respond to the stressors in their lives and in turn boost their sense of subjective wellbeing

Bailouts in a common market: a strategic approach

Governments in the EU grant Rescue and Restructure Subsidies to bail out ailing firms. In an international asymmetric Cournot duopoly we study effects of such subsidies on market structure and welfare. We adopt a common market setting, where consumers from the two countries form one market. We show that the subsidy is positive also when it fails to prevent the exit. The reason is a strategic effect, which forces the more efficient firm to make additional cost-reducing effort. When the exit is prevented, allocative and productive efficiencies are lower and the only gaining player is the rescued firm

Cholecystobronchocolic Fistula: A Late Complication of Biliary Sepsis

A case of a 48 year old woman presenting with bilioptysis due to a cholecystobronchocolic fistula is reported. Bilioptysis is a rare complication of biliary fistulae, with a high mortality due to chemical pneumonitis. Bronchospasm and rapid respiratory failure may ensue if aggressive management is not adopted. The site of fistulation is established by cholangiography, preferably by the percutaneous transhepatic route. Continued biliary drainage can lead to closure of these fistulae, or allow sufficient improvement in clinical condition to allow definitive surgery to be performed electively

Academic buoyancy, student's achievement, and the linking role of control: A cross-lagged analysis of high school students

Background Previous research has indicated that although academic buoyancy and student's achievement are associated, the relationship is relatively modest. Aims We sought to determine whether another construct might link academic buoyancy and student's achievement. Based on prior theoretical and empirical work, we examined a sense of control as one possible linking mechanism. Sample The study analysed data from 2,971 students attending 21 Australian high schools. Methods We conducted a cross-lagged panel design as a first means of disentangling the relative salience of academic buoyancy, control, and achievement (Phase 1). Based upon these results, we proceeded with follow-up analyses of an ordered process model linking the constructs over time (Phase 2). Results Findings showed that buoyancy and achievement were associated with control over time, but not with one another (Phase 1). In addition, control appeared to play a role in how buoyancy influenced achievement and that a cyclical process may operate among the three factors over time (Phase 2). Conclusion The findings suggest that control may play an important role in linking past experiences of academic buoyancy and achievement to subsequent academic buoyancy and achievement.The authors would like to thank the Australian Research Council for funding this research