| 1. |
- Jane, Stephen F., et al.
(author)
-
Widespread deoxygenation of temperate lakes
- 2021
-
In: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 594:7861, s. 66-70
-
Journal article (peer-reviewed)abstract
- The concentration of dissolved oxygen in aquatic systems helps to regulate biodiversity(1,2), nutrient biogeochemistry(3), greenhouse gas emissions(4), and the quality of drinking water(5). The long-term declines in dissolved oxygen concentrations in coastal and ocean waters have been linked to climate warming and human activity(6,7), but little is known about the changes in dissolved oxygen concentrations in lakes. Although the solubility of dissolved oxygen decreases with increasing water temperatures, long-term lake trajectories are difficult to predict. Oxygen losses in warming lakes may be amplified by enhanced decomposition and stronger thermal stratification(8,9) or oxygen may increase as a result of enhanced primary production(10). Here we analyse a combined total of 45,148 dissolved oxygen and temperature profiles and calculate trends for 393 temperate lakes that span 1941 to 2017. We find that a decline in dissolved oxygen is widespread in surface and deep-water habitats. The decline in surface waters is primarily associated with reduced solubility under warmer water temperatures, although dissolved oxygen in surface waters increased in a subset of highly productive warming lakes, probably owing to increasing production of phytoplankton. By contrast, the decline in deep waters is associated with stronger thermal stratification and loss of water clarity, but not with changes in gas solubility. Our results suggest that climate change and declining water clarity have altered the physical and chemical environment of lakes. Declines in dissolved oxygen in freshwater are 2.75 to 9.3 times greater than observed in the world's oceans(6,7) and could threaten essential lake ecosystem services(2,3,5,11).
|
|
| 2. |
- McCormack, Brendan, et al.
(author)
-
A realist review of interventions and strategies to promote evidence-informed healthcare : a focus on change agency
- 2013
-
In: Implementation Science. - : BioMed Central (BMC). - 1748-5908. ; 8:1, s. 107-
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Change agency in its various forms is one intervention aimed at improving the effectiveness of the uptake of evidence. Facilitators, knowledge brokers and opinion leaders are examples of change agency strategies used to promote knowledge utilization. This review adopts a realist approach and addresses the following question: What change agency characteristics work, for whom do they work, in what circumstances and why?METHODS: The literature reviewed spanned the period 1997-2007. Change agency was operationalized as roles that are aimed at effecting successful change in individuals and organizations. A theoretical framework, developed through stakeholder consultation formed the basis for a search for relevant literature. Team members, working in sub groups, independently themed the data and developed chains of inference to form a series of hypotheses regarding change agency and the role of change agency in knowledge use.RESULTS: 24, 478 electronic references were initially returned from search strategies. Preliminary screening of the article titles reduced the list of potentially relevant papers to 196. A review of full document versions of potentially relevant papers resulted in a final list of 52 papers. The findings add to the knowledge of change agency as they raise issues pertaining to how change agents' function, how individual change agent characteristics effect evidence-informed health care, the influence of interaction between the change agent and the setting and the overall effect of change agency on knowledge utilization. Particular issues are raised such as how accessibility of the change agent, their cultural compatibility and their attitude mediate overall effectiveness. Findings also indicate the importance of promoting reflection on practice and role modeling. The findings of this study are limited by the complexity and diversity of the change agency literature, poor indexing of literature and a lack of theory-driven approaches.CONCLUSION: This is the first realist review of change agency. Though effectiveness evidence is weak, change agent roles are evolving, as is the literature, which requires more detailed description of interventions, outcomes measures, the context, intensity, and levels at which interventions are implemented in order to understand how change agent interventions effect evidence-informed health care.
|
|
