Growth hormone affects behaviour of wild brown trout Salmo trutta in territorial owner–intruder conflicts

The effects of growth hormone (GH) implants on aggression, and ability to win dyadic territorial conflicts were studied in brown trout Salmo trutta parr. Bovine GH or vehicle (C) was given to either the territory owner or the intruder in four treatment combinations: C and C, C and GH, GH and C, GH and GH (owner and intruder). GH‐treated intruders initiated significantly more conflicts compared to control intruders. Furthermore, GH treatment of either the owner or intruder tended to increase aggression of the intruder. This indicates that intruders have more scope for motivational increase, while the motivation of owners is already at a maximum. The GH treatment, however, did not affect the outcome of the conflict. It thus appears that growth enhancement increases intruder aggression without increasing the chance of winning the conflict, which may have implications for the effect of growth‐selected or growth‐enhanced farmed Atlantic salmon Salmo salar on wild populations.     

Three research priorities for just and sustainable urban systems: Now is the time to refocus

Now is the time to refocus efforts in urban research and design. A changing climate and extreme weather events are presenting unique challenges to urban systems around the world. These challenges illuminate the social barriers that accompany disruptive events such as resource inequities and injustices. In this perspective, we provide three research priorities for just and sustainable urban systems that help to address these matters. The three research priorities are: (1) social equity and justice, (2) circularity, and (3) digital twins. Conceptual context and future research directions are provided for each. For social equity and justice, the future directions are mandatory equity analysis and inclusionary practices, understanding and reconciling historical injustices, and intentional integration with diverse community stakeholders. For circularity applications, they are better metrics for integration, more robust evaluation frameworks, and dynamic modeling at multiple spatial and temporal scales. Future directions for digital twins include developing principles to reduce complexity, integrating model and system components, and reducing barriers to data access. These research priorities are core to meeting several of the United Nations Sustainable Development Goals (i.e., 1—No Poverty, 8—Decent Work and Economic Growth, 10—Reduced Inequalities, and 11—Sustainable Cities and Communities). Useful social and technical matters are discussed throughout, where we highlight the importance of prioritizing localized research efforts, provide guidance for community-engaged research and co-development practices, and explain how these priorities interact to align with the evolving field of industrial ecology.     

Factors associated with maternal depressive symptoms among low-income,African American smokers enrolled in a secondhand smoke reduction programme

Introduction Maternal depressive symptoms increase the risk of poor maternal and child health outcomes, and are a primary barrier to health behaviour change. Social cognitive theory can guide our understanding of risk factors that may have an impact on maternal depressive symptoms. The aim of this paper was to understand the correlates of maternal depressive symptoms among low-income African American smokers completing a 16-week intervention trial to reduce young children''s second-hand smoke exposure (SHSe).Methods This study presents a secondary analysis of depression symptoms among 227 maternal smokers completing the SHSe-reduction trial. The end-of-treatment Center of Epidemiologic Studies Depression Scale (CES-D) score was used to assess depressive symptoms (dichotomised as 0 = score of < 16 and 1 = score of ≥ 16). Multivariate logistic regression analysis was used to test the one-way hypothesis that odds of significant depressive symptoms would be associated with greater total number of household smokers, greater number of paediatric sick visits, greater daily exposure of child to cigarette smoke by their mother, greater life-event stress, and lower social support, marital status, employment status and level of educational attainment.Results Number of household smokers (OR = 1.57, P = 0.049), social support (OR = 0.88, P < 0.001) and life-event stress (OR = 1.04, P = 0.001) predicted significant maternal depressive symptoms; all other variables were not significant predictors in the model.Conclusion Number of household smokers is a novel risk factor for understanding significant maternal depressive symptoms in the context of a childhood SHSe-reduction trial. Improving our understanding of the household-level social milieu in the context of SHSe-reduction interventions will assist in reducing the risk of maternal depressive symptoms.